A complete maintenance planning system (#1213)

A complete maintenance planning system from karelkryda/master
2024-11-10 23:54:13 -08:00 · 2022-10-15 20:54:28 +08:00 · 2022-10-15 20:54:28 +08:00 · afe12ccf24
parent b60dde0b2d 6f4424de28
commit afe12ccf24
45 changed files with 2680 additions and 70 deletions
--- a/db/patch-maintenance-table2.sql
+++ b/db/patch-maintenance-table2.sql
@ -0,0 +1,83 @@
+-- You should not modify if this have pushed to Github, unless it does serious wrong with the db.
+BEGIN TRANSACTION;
+
+-- Just for someone who tested maintenance before (patch-maintenance-table.sql)
+DROP TABLE IF EXISTS maintenance_status_page;
+DROP TABLE IF EXISTS monitor_maintenance;
+DROP TABLE IF EXISTS maintenance;
+DROP TABLE IF EXISTS maintenance_timeslot;
+
+-- maintenance
+CREATE TABLE [maintenance] (
+    [id] INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
+    [title] VARCHAR(150) NOT NULL,
+    [description] TEXT NOT NULL,
+    [user_id] INTEGER REFERENCES [user]([id]) ON DELETE SET NULL ON UPDATE CASCADE,
+    [active] BOOLEAN NOT NULL DEFAULT 1,
+    [strategy] VARCHAR(50) NOT NULL DEFAULT 'single',
+    [start_date] DATETIME,
+    [end_date] DATETIME,
+    [start_time] TIME,
+    [end_time] TIME,
+    [weekdays] VARCHAR2(250) DEFAULT '[]',
+    [days_of_month] TEXT DEFAULT '[]',
+    [interval_day] INTEGER
+);
+
+CREATE INDEX [manual_active] ON [maintenance] (
+    [strategy],
+    [active]
+);
+
+CREATE INDEX [active] ON [maintenance] ([active]);
+
+CREATE INDEX [maintenance_user_id] ON [maintenance] ([user_id]);
+
+-- maintenance_status_page
+CREATE TABLE maintenance_status_page (
+    id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
+    status_page_id INTEGER NOT NULL,
+    maintenance_id INTEGER NOT NULL,
+    CONSTRAINT FK_maintenance FOREIGN KEY (maintenance_id) REFERENCES maintenance (id) ON DELETE CASCADE ON UPDATE CASCADE,
+    CONSTRAINT FK_status_page FOREIGN KEY (status_page_id) REFERENCES status_page (id) ON DELETE CASCADE ON UPDATE CASCADE
+);
+
+CREATE INDEX [status_page_id_index]
+    ON [maintenance_status_page]([status_page_id]);
+
+CREATE INDEX [maintenance_id_index]
+    ON [maintenance_status_page]([maintenance_id]);
+
+-- maintenance_timeslot
+CREATE TABLE [maintenance_timeslot] (
+    [id] INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
+    [maintenance_id] INTEGER NOT NULL CONSTRAINT [FK_maintenance] REFERENCES [maintenance]([id]) ON DELETE CASCADE ON UPDATE CASCADE,
+    [start_date] DATETIME NOT NULL,
+    [end_date] DATETIME,
+    [generated_next] BOOLEAN DEFAULT 0
+);
+
+CREATE INDEX [maintenance_id] ON [maintenance_timeslot] ([maintenance_id] DESC);
+
+CREATE INDEX [active_timeslot_index] ON [maintenance_timeslot] (
+    [maintenance_id] DESC,
+    [start_date] DESC,
+    [end_date] DESC
+);
+
+CREATE INDEX [generated_next_index] ON [maintenance_timeslot] ([generated_next]);
+
+-- monitor_maintenance
+CREATE TABLE monitor_maintenance (
+    id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
+    monitor_id INTEGER NOT NULL,
+    maintenance_id INTEGER NOT NULL,
+    CONSTRAINT FK_maintenance FOREIGN KEY (maintenance_id) REFERENCES maintenance (id) ON DELETE CASCADE ON UPDATE CASCADE,
+    CONSTRAINT FK_monitor FOREIGN KEY (monitor_id) REFERENCES monitor (id) ON DELETE CASCADE ON UPDATE CASCADE
+);
+
+CREATE INDEX [maintenance_id_index2] ON [monitor_maintenance]([maintenance_id]);
+
+CREATE INDEX [monitor_id_index] ON [monitor_maintenance]([monitor_id]);
+
+COMMIT;
--- a/package-lock.json
+++ b/package-lock.json
@ -69,6 +69,7 @@
                "@vitejs/plugin-legacy": "~2.1.0",
                "@vitejs/plugin-vue": "~3.1.0",
                "@vue/compiler-sfc": "~3.2.36",
+                "@vuepic/vue-datepicker": "~3.4.8",
                "aedes": "^0.46.3",
                "babel-plugin-rewire": "~1.2.0",
                "bootstrap": "5.1.3",
@ -3925,6 +3926,21 @@
            "integrity": "sha512-dTyhTIRmGXBjxJE+skC8tTWCGLCVc4wQgRRLt8+O9p5ewBAjoBwtCAkLPrtToSr1xltoe3st21Pv953aOZ7alg==",
            "dev": true
        },
+        "node_modules/@vuepic/vue-datepicker": {
+            "version": "3.4.8",
+            "resolved": "https://registry.npmjs.org/@vuepic/vue-datepicker/-/vue-datepicker-3.4.8.tgz",
+            "integrity": "sha512-nbuMA7IgjtT99LqcjSTSUcl7omTZSB+7vYSWQ9gQm31Frm/1wn54fT1Q0HaRD9nHXX982AACbqeND4K80SKONw==",
+            "dev": true,
+            "dependencies": {
+                "date-fns": "^2.29.2"
+            },
+            "engines": {
+                "node": ">=14"
+            },
+            "peerDependencies": {
+                "vue": ">=3.2.0"
+            }
+        },
        "node_modules/abab": {
            "version": "2.0.6",
            "resolved": "https://registry.npmjs.org/abab/-/abab-2.0.6.tgz",
@ -19613,6 +19629,15 @@
            "integrity": "sha512-dTyhTIRmGXBjxJE+skC8tTWCGLCVc4wQgRRLt8+O9p5ewBAjoBwtCAkLPrtToSr1xltoe3st21Pv953aOZ7alg==",
            "dev": true
        },
+        "@vuepic/vue-datepicker": {
+            "version": "3.4.8",
+            "resolved": "https://registry.npmjs.org/@vuepic/vue-datepicker/-/vue-datepicker-3.4.8.tgz",
+            "integrity": "sha512-nbuMA7IgjtT99LqcjSTSUcl7omTZSB+7vYSWQ9gQm31Frm/1wn54fT1Q0HaRD9nHXX982AACbqeND4K80SKONw==",
+            "dev": true,
+            "requires": {
+                "date-fns": "^2.29.2"
+            }
+        },
        "abab": {
            "version": "2.0.6",
            "resolved": "https://registry.npmjs.org/abab/-/abab-2.0.6.tgz",
--- a/package.json
+++ b/package.json
@ -123,6 +123,7 @@
        "@vitejs/plugin-legacy": "~2.1.0",
        "@vitejs/plugin-vue": "~3.1.0",
        "@vue/compiler-sfc": "~3.2.36",
+        "@vuepic/vue-datepicker": "~3.4.8",
        "aedes": "^0.46.3",
        "babel-plugin-rewire": "~1.2.0",
        "bootstrap": "5.1.3",
--- a/server/client.js
+++ b/server/client.js
@ -4,7 +4,8 @@
 const { TimeLogger } = require("../src/util");
 const { R } = require("redbean-node");
 const { UptimeKumaServer } = require("./uptime-kuma-server");
-const io = UptimeKumaServer.getInstance().io;
+const server = UptimeKumaServer.getInstance();
+const io = server.io;
 const { setting } = require("./util-server");
 const checkVersion = require("./check-version");

@ -121,7 +122,9 @@ async function sendInfo(socket) {
    socket.emit("info", {
        version: checkVersion.version,
        latestVersion: checkVersion.latestVersion,
-        primaryBaseURL: await setting("primaryBaseURL")
+        primaryBaseURL: await setting("primaryBaseURL"),
+        serverTimezone: await server.getTimezone(),
+        serverTimezoneOffset: server.getTimezoneOffset(),
    });
 }

--- a/server/database.js
+++ b/server/database.js
@ -64,6 +64,7 @@ class Database {
        "patch-add-other-auth.sql": { parents: [ "patch-monitor-basic-auth.sql" ] },
        "patch-add-radius-monitor.sql": true,
        "patch-monitor-add-resend-interval.sql": true,
+        "patch-maintenance-table2.sql": true,
    };

    /**
--- a/server/model/heartbeat.js
+++ b/server/model/heartbeat.js
@ -1,8 +1,4 @@
 const dayjs = require("dayjs");
-const utc = require("dayjs/plugin/utc");
-let timezone = require("dayjs/plugin/timezone");
-dayjs.extend(utc);
-dayjs.extend(timezone);
 const { BeanModel } = require("redbean-node/dist/bean-model");

 /**
@ -10,6 +6,7 @@ const { BeanModel } = require("redbean-node/dist/bean-model");
 *      0 = DOWN
 *      1 = UP
 *      2 = PENDING
+ *      3 = MAINTENANCE
 */
 class Heartbeat extends BeanModel {

--- a/server/model/maintenance.js
+++ b/server/model/maintenance.js
@ -0,0 +1,215 @@
+const { BeanModel } = require("redbean-node/dist/bean-model");
+const { parseTimeObject, parseTimeFromTimeObject, utcToLocal, localToUTC, log } = require("../../src/util");
+const { timeObjectToUTC, timeObjectToLocal } = require("../util-server");
+const { R } = require("redbean-node");
+const dayjs = require("dayjs");
+
+class Maintenance extends BeanModel {
+
+    /**
+     * Return an object that ready to parse to JSON for public
+     * Only show necessary data to public
+     * @returns {Object}
+     */
+    async toPublicJSON() {
+
+        let dateRange = [];
+        if (this.start_date) {
+            dateRange.push(utcToLocal(this.start_date));
+            if (this.end_date) {
+                dateRange.push(utcToLocal(this.end_date));
+            }
+        }
+
+        let timeRange = [];
+        let startTime = timeObjectToLocal(parseTimeObject(this.start_time));
+        timeRange.push(startTime);
+        let endTime = timeObjectToLocal(parseTimeObject(this.end_time));
+        timeRange.push(endTime);
+
+        let obj = {
+            id: this.id,
+            title: this.title,
+            description: this.description,
+            strategy: this.strategy,
+            intervalDay: this.interval_day,
+            active: !!this.active,
+            dateRange: dateRange,
+            timeRange: timeRange,
+            weekdays: (this.weekdays) ? JSON.parse(this.weekdays) : [],
+            daysOfMonth: (this.days_of_month) ? JSON.parse(this.days_of_month) : [],
+            timeslotList: [],
+        };
+
+        const timeslotList = await this.getTimeslotList();
+
+        for (let timeslot of timeslotList) {
+            obj.timeslotList.push(await timeslot.toPublicJSON());
+        }
+
+        if (!Array.isArray(obj.weekdays)) {
+            obj.weekdays = [];
+        }
+
+        if (!Array.isArray(obj.daysOfMonth)) {
+            obj.daysOfMonth = [];
+        }
+
+        // Maintenance Status
+        if (!obj.active) {
+            obj.status = "inactive";
+        } else if (obj.strategy === "manual") {
+            obj.status = "under-maintenance";
+        } else if (obj.timeslotList.length > 0) {
+            let currentTimestamp = dayjs().unix();
+
+            for (let timeslot of obj.timeslotList) {
+                if (dayjs.utc(timeslot.startDate).unix() <= currentTimestamp && dayjs.utc(timeslot.endDate).unix() >= currentTimestamp) {
+                    log.debug("timeslot", "Timeslot ID: " + timeslot.id);
+                    log.debug("timeslot", "currentTimestamp:" + currentTimestamp);
+                    log.debug("timeslot", "timeslot.start_date:" + dayjs.utc(timeslot.startDate).unix());
+                    log.debug("timeslot", "timeslot.end_date:" + dayjs.utc(timeslot.endDate).unix());
+
+                    obj.status = "under-maintenance";
+                    break;
+                }
+            }
+
+            if (!obj.status) {
+                obj.status = "scheduled";
+            }
+        } else if (obj.timeslotList.length === 0) {
+            obj.status = "ended";
+        } else {
+            obj.status = "unknown";
+        }
+
+        return obj;
+    }
+
+    /**
+     * Only get future or current timeslots only
+     * @returns {Promise<[]>}
+     */
+    async getTimeslotList() {
+        return R.convertToBeans("maintenance_timeslot", await R.getAll(`
+            SELECT maintenance_timeslot.*
+            FROM maintenance_timeslot, maintenance
+            WHERE maintenance_timeslot.maintenance_id = maintenance.id
+            AND maintenance.id = ?
+            AND ${Maintenance.getActiveAndFutureMaintenanceSQLCondition()}
+        `, [
+            this.id
+        ]));
+    }
+
+    /**
+     * Return an object that ready to parse to JSON
+     * @param {string} timezone If not specified, the timeRange will be in UTC
+     * @returns {Object}
+     */
+    async toJSON(timezone = null) {
+        return this.toPublicJSON(timezone);
+    }
+
+    getDayOfWeekList() {
+        log.debug("timeslot", "List: " + this.weekdays);
+        return JSON.parse(this.weekdays).sort(function (a, b) {
+            return a - b;
+        });
+    }
+
+    getDayOfMonthList() {
+        return JSON.parse(this.days_of_month).sort(function (a, b) {
+            return a - b;
+        });
+    }
+
+    getStartDateTime() {
+        let startOfTheDay = dayjs.utc(this.start_date).format("HH:mm");
+        log.debug("timeslot", "startOfTheDay: " + startOfTheDay);
+
+        // Start Time
+        let startTimeSecond = dayjs.utc(this.start_time, "HH:mm").diff(dayjs.utc(startOfTheDay, "HH:mm"), "second");
+        log.debug("timeslot", "startTime: " + startTimeSecond);
+
+        // Bake StartDate + StartTime = Start DateTime
+        return dayjs.utc(this.start_date).add(startTimeSecond, "second");
+    }
+
+    getDuration() {
+        let duration = dayjs.utc(this.end_time, "HH:mm").diff(dayjs.utc(this.start_time, "HH:mm"), "second");
+        // Add 24hours if it is across day
+        if (duration < 0) {
+            duration += 24 * 3600;
+        }
+        return duration;
+    }
+
+    static jsonToBean(bean, obj) {
+        if (obj.id) {
+            bean.id = obj.id;
+        }
+
+        // Apply timezone offset to timeRange, as it cannot apply automatically.
+        if (obj.timeRange[0]) {
+            timeObjectToUTC(obj.timeRange[0]);
+            if (obj.timeRange[1]) {
+                timeObjectToUTC(obj.timeRange[1]);
+            }
+        }
+
+        bean.title = obj.title;
+        bean.description = obj.description;
+        bean.strategy = obj.strategy;
+        bean.interval_day = obj.intervalDay;
+        bean.active = obj.active;
+
+        if (obj.dateRange[0]) {
+            bean.start_date = localToUTC(obj.dateRange[0]);
+
+            if (obj.dateRange[1]) {
+                bean.end_date = localToUTC(obj.dateRange[1]);
+            }
+        }
+
+        bean.start_time = parseTimeFromTimeObject(obj.timeRange[0]);
+        bean.end_time = parseTimeFromTimeObject(obj.timeRange[1]);
+
+        bean.weekdays = JSON.stringify(obj.weekdays);
+        bean.days_of_month = JSON.stringify(obj.daysOfMonth);
+
+        return bean;
+    }
+
+    /**
+     * SQL conditions for active maintenance
+     * @returns {string}
+     */
+    static getActiveMaintenanceSQLCondition() {
+        return `
+
+            (maintenance_timeslot.start_date <= DATETIME('now')
+            AND maintenance_timeslot.end_date >= DATETIME('now')
+            AND maintenance.active = 1)
+            OR
+            (maintenance.strategy = 'manual' AND active = 1)
+
+        `;
+    }
+
+    /**
+     * SQL conditions for active and future maintenance
+     * @returns {string}
+     */
+    static getActiveAndFutureMaintenanceSQLCondition() {
+        return `
+            ((maintenance_timeslot.end_date >= DATETIME('now')
+            AND maintenance.active = 1)
+            OR
+            (maintenance.strategy = 'manual' AND active = 1))
+        `;
+    }
+}
+
+module.exports = Maintenance;
--- a/server/model/maintenance_timeslot.js
+++ b/server/model/maintenance_timeslot.js
@ -0,0 +1,189 @@
+const { BeanModel } = require("redbean-node/dist/bean-model");
+const { R } = require("redbean-node");
+const dayjs = require("dayjs");
+const { log, utcToLocal, SQL_DATETIME_FORMAT_WITHOUT_SECOND, localToUTC } = require("../../src/util");
+const { UptimeKumaServer } = require("../uptime-kuma-server");
+
+class MaintenanceTimeslot extends BeanModel {
+
+    async toPublicJSON() {
+        const serverTimezoneOffset = UptimeKumaServer.getInstance().getTimezoneOffset();
+
+        const obj = {
+            id: this.id,
+            startDate: this.start_date,
+            endDate: this.end_date,
+            startDateServerTimezone: utcToLocal(this.start_date, SQL_DATETIME_FORMAT_WITHOUT_SECOND),
+            endDateServerTimezone: utcToLocal(this.end_date, SQL_DATETIME_FORMAT_WITHOUT_SECOND),
+            serverTimezoneOffset,
+        };
+
+        return obj;
+    }
+
+    async toJSON() {
+        return await this.toPublicJSON();
+    }
+
+    /**
+     * @param {Maintenance} maintenance
+     * @param {dayjs} minDate (For recurring type only) Generate a next timeslot from this date.
+     * @param {boolean} removeExist Remove existing timeslot before create
+     * @returns {Promise<MaintenanceTimeslot>}
+     */
+    static async generateTimeslot(maintenance, minDate = null, removeExist = false) {
+        if (removeExist) {
+            await R.exec("DELETE FROM maintenance_timeslot WHERE maintenance_id = ? ", [
+                maintenance.id
+            ]);
+        }
+
+        if (maintenance.strategy === "manual") {
+            log.debug("maintenance", "No need to generate timeslot for manual type");
+
+        } else if (maintenance.strategy === "single") {
+            let bean = R.dispense("maintenance_timeslot");
+            bean.maintenance_id = maintenance.id;
+            bean.start_date = maintenance.start_date;
+            bean.end_date = maintenance.end_date;
+            bean.generated_next = true;
+            return await R.store(bean);
+
+        } else if (maintenance.strategy === "recurring-interval") {
+            // Prevent dead loop, in case interval_day is not set
+            if (!maintenance.interval_day || maintenance.interval_day <= 0) {
+                maintenance.interval_day = 1;
+            }
+
+            return await this.handleRecurringType(maintenance, minDate, (startDateTime) => {
+                return startDateTime.add(maintenance.interval_day, "day");
+            }, () => {
+                return true;
+            });
+
+        } else if (maintenance.strategy === "recurring-weekday") {
+            let dayOfWeekList = maintenance.getDayOfWeekList();
+            log.debug("timeslot", dayOfWeekList);
+
+            if (dayOfWeekList.length <= 0) {
+                log.debug("timeslot", "No weekdays selected?");
+                return null;
+            }
+
+            const isValid = (startDateTime) => {
+                log.debug("timeslot", "nextDateTime: " + startDateTime);
+
+                let day = startDateTime.local().day();
+                log.debug("timeslot", "nextDateTime.day(): " + day);
+
+                return dayOfWeekList.includes(day);
+            };
+
+            return await this.handleRecurringType(maintenance, minDate, (startDateTime) => {
+                while (true) {
+                    startDateTime = startDateTime.add(1, "day");
+
+                    if (isValid(startDateTime)) {
+                        return startDateTime;
+                    }
+                }
+            }, isValid);
+
+        } else if (maintenance.strategy === "recurring-day-of-month") {
+            let dayOfMonthList = maintenance.getDayOfMonthList();
+            if (dayOfMonthList.length <= 0) {
+                log.debug("timeslot", "No day selected?");
+                return null;
+            }
+
+            const isValid = (startDateTime) => {
+                let day = parseInt(startDateTime.local().format("D"));
+
+                log.debug("timeslot", "day: " + day);
+
+                // Check 1-31
+                if (dayOfMonthList.includes(day)) {
+                    return startDateTime;
+                }
+
+                // Check "lastDay1","lastDay2"...
+                let daysInMonth = startDateTime.daysInMonth();
+                let lastDayList = [];
+
+                // Small first, e.g. 28 > 29 > 30 > 31
+                for (let i = 4; i >= 1; i--) {
+                    if (dayOfMonthList.includes("lastDay" + i)) {
+                        lastDayList.push(daysInMonth - i + 1);
+                    }
+                }
+                log.debug("timeslot", lastDayList);
+                return lastDayList.includes(day);
+            };
+
+            return await this.handleRecurringType(maintenance, minDate, (startDateTime) => {
+                while (true) {
+                    startDateTime = startDateTime.add(1, "day");
+                    if (isValid(startDateTime)) {
+                        return startDateTime;
+                    }
+                }
+            }, isValid);
+        } else {
+            throw new Error("Unknown maintenance strategy");
+        }
+    }
+
+    /**
+     * Generate a next timeslot for all recurring types
+     * @param maintenance
+     * @param minDate
+     * @param {function} nextDayCallback The logic how to get the next possible day
+     * @param {function} isValidCallback Check the day whether is matched the current strategy
+     * @returns {Promise<null|MaintenanceTimeslot>}
+     */
+    static async handleRecurringType(maintenance, minDate, nextDayCallback, isValidCallback) {
+        let bean = R.dispense("maintenance_timeslot");
+
+        let duration = maintenance.getDuration();
+        let startDateTime = maintenance.getStartDateTime();
+        let endDateTime;
+
+        // Keep generating from the first possible date, until it is ok
+        while (true) {
+            log.debug("timeslot", "startDateTime: " + startDateTime.format());
+
+            // Handling out of effective date range
+            if (startDateTime.diff(dayjs.utc(maintenance.end_date)) > 0) {
+                log.debug("timeslot", "Out of effective date range");
+                return null;
+            }
+
+            endDateTime = startDateTime.add(duration, "second");
+
+            // If endDateTime is out of effective date range, use the end datetime from effective date range
+            if (endDateTime.diff(dayjs.utc(maintenance.end_date)) > 0) {
+                endDateTime = dayjs.utc(maintenance.end_date);
+            }
+
+            // If minDate is set, the endDateTime must be bigger than it.
+            // And the endDateTime must be bigger current time
+            // Is valid under current recurring strategy
+            if (
+                (!minDate || endDateTime.diff(minDate) > 0) &&
+                endDateTime.diff(dayjs()) > 0 &&
+                isValidCallback(startDateTime)
+            ) {
+                break;
+            }
+            startDateTime = nextDayCallback(startDateTime);
+        }
+
+        bean.maintenance_id = maintenance.id;
+        bean.start_date = localToUTC(startDateTime);
+        bean.end_date = localToUTC(endDateTime);
+        bean.generated_next = false;
+        return await R.store(bean);
+    }
+}
+
+module.exports = MaintenanceTimeslot;
--- a/server/model/monitor.js
+++ b/server/model/monitor.js
@ -1,12 +1,8 @@
 const https = require("https");
 const dayjs = require("dayjs");
-const utc = require("dayjs/plugin/utc");
-let timezone = require("dayjs/plugin/timezone");
-dayjs.extend(utc);
-dayjs.extend(timezone);
 const axios = require("axios");
 const { Prometheus } = require("../prometheus");
-const { log, UP, DOWN, PENDING, flipStatus, TimeLogger } = require("../../src/util");
+const { log, UP, DOWN, PENDING, MAINTENANCE, flipStatus, TimeLogger } = require("../../src/util");
 const { tcping, ping, dnsResolve, checkCertificate, checkStatusCode, getTotalClientInRoom, setting, mssqlQuery, postgresQuery, mqttAsync, setSetting, httpNtlm, radius } = require("../util-server");
 const { R } = require("redbean-node");
 const { BeanModel } = require("redbean-node/dist/bean-model");
@ -18,12 +14,14 @@ const apicache = require("../modules/apicache");
 const { UptimeKumaServer } = require("../uptime-kuma-server");
 const { CacheableDnsHttpAgent } = require("../cacheable-dns-http-agent");
 const { DockerHost } = require("../docker");
+const Maintenance = require("./maintenance");

 /**
 * status:
 *      0 = DOWN
 *      1 = UP
 *      2 = PENDING
+ *      3 = MAINTENANCE
 */
 class Monitor extends BeanModel {

@ -37,6 +35,7 @@ class Monitor extends BeanModel {
            id: this.id,
            name: this.name,
            sendUrl: this.sendUrl,
+            maintenance: await Monitor.isUnderMaintenance(this.id),
        };

        if (this.sendUrl) {
@ -96,6 +95,7 @@ class Monitor extends BeanModel {
            proxyId: this.proxy_id,
            notificationIDList,
            tags: tags,
+            maintenance: await Monitor.isUnderMaintenance(this.id),
            mqttUsername: this.mqttUsername,
            mqttPassword: this.mqttPassword,
            mqttTopic: this.mqttTopic,
@ -230,7 +230,10 @@ class Monitor extends BeanModel {
            }

            try {
-                if (this.type === "http" || this.type === "keyword") {
+                if (await Monitor.isUnderMaintenance(this.id)) {
+                    bean.msg = "Monitor under maintenance";
+                    bean.status = MAINTENANCE;
+                } else if (this.type === "http" || this.type === "keyword") {
                    // Do not do any queries/high loading things before the "bean.ping"
                    let startTime = dayjs().valueOf();

@ -606,8 +609,12 @@ class Monitor extends BeanModel {
            if (isImportant) {
                bean.important = true;

-                log.debug("monitor", `[${this.name}] sendNotification`);
-                await Monitor.sendNotification(isFirstBeat, this, bean);
+                if (Monitor.isImportantForNotification(isFirstBeat, previousBeat?.status, bean.status)) {
+                    log.debug("monitor", `[${this.name}] sendNotification`);
+                    await Monitor.sendNotification(isFirstBeat, this, bean);
+                } else {
+                    log.debug("monitor", `[${this.name}] will not sendNotification because it is (or was) under maintenance`);
+                }

                // Reset down count
                bean.downCount = 0;
@ -616,6 +623,8 @@ class Monitor extends BeanModel {
                log.debug("monitor", `[${this.name}] apicache clear`);
                apicache.clear();

+                UptimeKumaServer.getInstance().sendMaintenanceListByUserID(this.user_id);
+
            } else {
                bean.important = false;

@ -639,6 +648,8 @@ class Monitor extends BeanModel {
                    beatInterval = this.retryInterval;
                }
                log.warn("monitor", `Monitor #${this.id} '${this.name}': Pending: ${bean.msg} | Max retries: ${this.maxretries} | Retry: ${retries} | Retry Interval: ${beatInterval} seconds | Type: ${this.type}`);
+            } else if (bean.status === MAINTENANCE) {
+                log.warn("monitor", `Monitor #${this.id} '${this.name}': Under Maintenance | Type: ${this.type}`);
            } else {
                log.warn("monitor", `Monitor #${this.id} '${this.name}': Failing: ${bean.msg} | Interval: ${beatInterval} seconds | Type: ${this.type} | Down Count: ${bean.downCount} | Resend Interval: ${this.resendInterval}`);
            }
@ -849,7 +860,7 @@ class Monitor extends BeanModel {
               -- SUM all uptime duration, also trim off the beat out of time window
                SUM(
                    CASE
-                        WHEN (status = 1)
+                        WHEN (status = 1 OR status = 3)
                        THEN
                            CASE
                                WHEN (JULIANDAY(\`time\`) - JULIANDAY(?)) * 86400 < duration
@ -920,11 +931,49 @@ class Monitor extends BeanModel {
        // DOWN -> PENDING = this case not exists
        // DOWN -> DOWN = not important
        // * DOWN -> UP = important
-        let isImportant = isFirstBeat ||
+        // MAINTENANCE -> MAINTENANCE = not important
+        // * MAINTENANCE -> UP = important
+        // * MAINTENANCE -> DOWN = important
+        // * DOWN -> MAINTENANCE = important
+        // * UP -> MAINTENANCE = important
+        return isFirstBeat ||
+            (previousBeatStatus === DOWN && currentBeatStatus === MAINTENANCE) ||
+            (previousBeatStatus === UP && currentBeatStatus === MAINTENANCE) ||
+            (previousBeatStatus === MAINTENANCE && currentBeatStatus === DOWN) ||
+            (previousBeatStatus === MAINTENANCE && currentBeatStatus === UP) ||
+            (previousBeatStatus === UP && currentBeatStatus === DOWN) ||
+            (previousBeatStatus === DOWN && currentBeatStatus === UP) ||
+            (previousBeatStatus === PENDING && currentBeatStatus === DOWN);
+    }
+
+    /**
+     * Is this beat important for notifications?
+     * @param {boolean} isFirstBeat Is this the first beat of this monitor?
+     * @param {const} previousBeatStatus Status of the previous beat
+     * @param {const} currentBeatStatus Status of the current beat
+     * @returns {boolean} True if is an important beat else false
+     */
+    static isImportantForNotification(isFirstBeat, previousBeatStatus, currentBeatStatus) {
+        // * ? -> ANY STATUS = important [isFirstBeat]
+        // UP -> PENDING = not important
+        // * UP -> DOWN = important
+        // UP -> UP = not important
+        // PENDING -> PENDING = not important
+        // * PENDING -> DOWN = important
+        // PENDING -> UP = not important
+        // DOWN -> PENDING = this case not exists
+        // DOWN -> DOWN = not important
+        // * DOWN -> UP = important
+        // MAINTENANCE -> MAINTENANCE = not important
+        // MAINTENANCE -> UP = not important
+        // * MAINTENANCE -> DOWN = important
+        // DOWN -> MAINTENANCE = not important
+        // UP -> MAINTENANCE = not important
+        return isFirstBeat ||
+            (previousBeatStatus === MAINTENANCE && currentBeatStatus === DOWN) ||
            (previousBeatStatus === UP && currentBeatStatus === DOWN) ||
            (previousBeatStatus === DOWN && currentBeatStatus === UP) ||
            (previousBeatStatus === PENDING && currentBeatStatus === DOWN);
-        return isImportant;
    }

    /**
@ -1061,6 +1110,26 @@ class Monitor extends BeanModel {
            monitorID
        ]);
    }
+
+    /**
+     * Check if monitor is under maintenance
+     * @param {number} monitorID ID of monitor to check
+     * @returns {Promise<boolean>}
+     */
+    static async isUnderMaintenance(monitorID) {
+        let activeCondition = Maintenance.getActiveMaintenanceSQLCondition();
+        const maintenance = await R.getRow(`
+            SELECT COUNT(*) AS count
+            FROM monitor_maintenance mm
+            JOIN maintenance
+                ON mm.maintenance_id = maintenance.id
+                AND mm.monitor_id = ?
+            LEFT JOIN maintenance_timeslot
+                ON maintenance_timeslot.maintenance_id = maintenance.id
+            WHERE ${activeCondition}
+            LIMIT 1`, [ monitorID ]);
+        return maintenance.count !== 0;
+    }
 }

 module.exports = Monitor;
--- a/server/model/status_page.js
+++ b/server/model/status_page.js
@ -3,6 +3,7 @@ const { R } = require("redbean-node");
 const cheerio = require("cheerio");
 const { UptimeKumaServer } = require("../uptime-kuma-server");
 const jsesc = require("jsesc");
+const Maintenance = require("./maintenance");

 class StatusPage extends BeanModel {

@ -90,6 +91,8 @@ class StatusPage extends BeanModel {
            incident = incident.toPublicJSON();
        }

+        let maintenanceList = await StatusPage.getMaintenanceList(statusPage.id);
+
        // Public Group List
        const publicGroupList = [];
        const showTags = !!statusPage.show_tags;
@ -107,7 +110,8 @@ class StatusPage extends BeanModel {
        return {
            config: await statusPage.toPublicJSON(),
            incident,
-            publicGroupList
+            publicGroupList,
+            maintenanceList,
        };
    }

@ -266,6 +270,36 @@ class StatusPage extends BeanModel {
        }
    }

+    /**
+     * Get list of maintenances
+     * @param {number} statusPageId ID of status page to get maintenance for
+     * @returns {Object} Object representing maintenances sanitized for public
+     */
+    static async getMaintenanceList(statusPageId) {
+        try {
+            const publicMaintenanceList = [];
+
+            let activeCondition = Maintenance.getActiveMaintenanceSQLCondition();
+            let maintenanceBeanList = R.convertToBeans("maintenance", await R.getAll(`
+                SELECT maintenance.*
+                FROM maintenance, maintenance_status_page msp, maintenance_timeslot
+                WHERE msp.maintenance_id = maintenance.id
+                    AND maintenance_timeslot.maintenance_id = maintenance.id
+                    AND msp.status_page_id = ?
+                    AND ${activeCondition}
+                ORDER BY maintenance.end_date
+            `, [ statusPageId ]));
+
+            for (const bean of maintenanceBeanList) {
+                publicMaintenanceList.push(await bean.toPublicJSON());
+            }
+
+            return publicMaintenanceList;
+
+        } catch (error) {
+            return [];
+        }
+    }
 }

 module.exports = StatusPage;
--- a/server/routers/api-router.js
+++ b/server/routers/api-router.js
@ -4,7 +4,7 @@ const { R } = require("redbean-node");
 const apicache = require("../modules/apicache");
 const Monitor = require("../model/monitor");
 const dayjs = require("dayjs");
-const { UP, DOWN, flipStatus, log } = require("../../src/util");
+const { UP, MAINTENANCE, DOWN, flipStatus, log } = require("../../src/util");
 const StatusPage = require("../model/status_page");
 const { UptimeKumaServer } = require("../uptime-kuma-server");
 const { makeBadge } = require("badge-maker");
@ -67,6 +67,11 @@ router.get("/api/push/:pushToken", async (request, response) => {
            duration = dayjs(bean.time).diff(dayjs(previousHeartbeat.time), "second");
        }

+        if (await Monitor.isUnderMaintenance(monitor.id)) {
+            msg = "Monitor under maintenance";
+            status = MAINTENANCE;
+        }
+
        log.debug("router", `/api/push/ called at ${dayjs().format("YYYY-MM-DD HH:mm:ss.SSS")}`);
        log.debug("router", "PreviousStatus: " + previousStatus);
        log.debug("router", "Current Status: " + status);
@ -87,7 +92,7 @@ router.get("/api/push/:pushToken", async (request, response) => {
            ok: true,
        });

-        if (bean.important) {
+        if (Monitor.isImportantForNotification(isFirstBeat, previousStatus, status)) {
            await Monitor.sendNotification(isFirstBeat, monitor, bean);
        }

--- a/server/server.js
+++ b/server/server.js
@ -5,6 +5,12 @@
 */
 console.log("Welcome to Uptime Kuma");

+// As the log function need to use dayjs, it should be very top
+const dayjs = require("dayjs");
+dayjs.extend(require("dayjs/plugin/utc"));
+dayjs.extend(require("dayjs/plugin/timezone"));
+dayjs.extend(require("dayjs/plugin/customParseFormat"));
+
 // Check Node.js Version
 const nodeVersion = parseInt(process.versions.node.split(".")[0]);
 const requiredVersion = 14;
@ -33,6 +39,7 @@ log.info("server", "Importing Node libraries");
 const fs = require("fs");

 log.info("server", "Importing 3rd-party libraries");
+
 log.debug("server", "Importing express");
 const express = require("express");
 const expressStaticGzip = require("express-static-gzip");
@ -127,6 +134,7 @@ const StatusPage = require("./model/status_page");
 const { cloudflaredSocketHandler, autoStart: cloudflaredAutoStart, stop: cloudflaredStop } = require("./socket-handlers/cloudflared-socket-handler");
 const { proxySocketHandler } = require("./socket-handlers/proxy-socket-handler");
 const { dockerSocketHandler } = require("./socket-handlers/docker-socket-handler");
+const { maintenanceSocketHandler } = require("./socket-handlers/maintenance-socket-handler");
 const { Settings } = require("./settings");

 app.use(express.json());
@ -155,6 +163,7 @@ let needSetup = false;
 (async () => {
    Database.init(args);
    await initDatabase(testMode);
+    await server.initAfterDatabaseReady();

    server.entryPage = await Settings.get("entryPage");
    await StatusPage.loadDomainMappingList();
@ -1057,10 +1066,15 @@ let needSetup = false;
        socket.on("getSettings", async (callback) => {
            try {
                checkLogin(socket);
+                const data = await getSettings("general");
+
+                if (!data.serverTimezone) {
+                    data.serverTimezone = await server.getTimezone();
+                }

                callback({
                    ok: true,
-                    data: await getSettings("general"),
+                    data: data,
                });

            } catch (e) {
@ -1088,12 +1102,18 @@ let needSetup = false;
                await setSettings("general", data);
                server.entryPage = data.entryPage;

+                // Also need to apply timezone globally
+                if (data.serverTimezone) {
+                    await server.setTimezone(data.serverTimezone);
+                }
+
                callback({
                    ok: true,
                    msg: "Saved"
                });

                sendInfo(socket);
+                server.sendMaintenanceList(socket);

            } catch (e) {
                callback({
@ -1452,6 +1472,7 @@ let needSetup = false;
        databaseSocketHandler(socket);
        proxySocketHandler(socket);
        dockerSocketHandler(socket);
+        maintenanceSocketHandler(socket);

        log.debug("server", "added all socket handlers");

@ -1554,6 +1575,7 @@ async function afterLogin(socket, user) {
    socket.join(user.id);

    let monitorList = await server.sendMonitorList(socket);
+    server.sendMaintenanceList(socket);
    sendNotificationList(socket);
    sendProxyList(socket);
    sendDockerHostList(socket);
@ -1699,6 +1721,8 @@ async function shutdownFunction(signal) {
    log.info("server", "Shutdown requested");
    log.info("server", "Called signal: " + signal);

+    await server.stop();
+
    log.info("server", "Stopping all monitors");
    for (let id in server.monitorList) {
        let monitor = server.monitorList[id];
--- a/server/socket-handlers/maintenance-socket-handler.js
+++ b/server/socket-handlers/maintenance-socket-handler.js
@ -0,0 +1,311 @@
+const { checkLogin } = require("../util-server");
+const { log } = require("../../src/util");
+const { R } = require("redbean-node");
+const apicache = require("../modules/apicache");
+const { UptimeKumaServer } = require("../uptime-kuma-server");
+const Maintenance = require("../model/maintenance");
+const server = UptimeKumaServer.getInstance();
+const MaintenanceTimeslot = require("../model/maintenance_timeslot");
+
+/**
+ * Handlers for Maintenance
+ * @param {Socket} socket Socket.io instance
+ */
+module.exports.maintenanceSocketHandler = (socket) => {
+    // Add a new maintenance
+    socket.on("addMaintenance", async (maintenance, callback) => {
+        try {
+            checkLogin(socket);
+
+            log.debug("maintenance", maintenance);
+
+            let bean = Maintenance.jsonToBean(R.dispense("maintenance"), maintenance);
+            bean.user_id = socket.userID;
+            let maintenanceID = await R.store(bean);
+            await MaintenanceTimeslot.generateTimeslot(bean);
+
+            await server.sendMaintenanceList(socket);
+
+            callback({
+                ok: true,
+                msg: "Added Successfully.",
+                maintenanceID,
+            });
+
+        } catch (e) {
+            callback({
+                ok: false,
+                msg: e.message,
+            });
+        }
+    });
+
+    // Edit a maintenance
+    socket.on("editMaintenance", async (maintenance, callback) => {
+        try {
+            checkLogin(socket);
+
+            let bean = await R.findOne("maintenance", " id = ? ", [ maintenance.id ]);
+
+            if (bean.user_id !== socket.userID) {
+                throw new Error("Permission denied.");
+            }
+
+            Maintenance.jsonToBean(bean, maintenance);
+
+            await R.store(bean);
+            await MaintenanceTimeslot.generateTimeslot(bean, null, true);
+
+            await server.sendMaintenanceList(socket);
+
+            callback({
+                ok: true,
+                msg: "Saved.",
+                maintenanceID: bean.id,
+            });
+
+        } catch (e) {
+            console.error(e);
+            callback({
+                ok: false,
+                msg: e.message,
+            });
+        }
+    });
+
+    // Add a new monitor_maintenance
+    socket.on("addMonitorMaintenance", async (maintenanceID, monitors, callback) => {
+        try {
+            checkLogin(socket);
+
+            await R.exec("DELETE FROM monitor_maintenance WHERE maintenance_id = ?", [
+                maintenanceID
+            ]);
+
+            for await (const monitor of monitors) {
+                let bean = R.dispense("monitor_maintenance");
+
+                bean.import({
+                    monitor_id: monitor.id,
+                    maintenance_id: maintenanceID
+                });
+                await R.store(bean);
+            }
+
+            apicache.clear();
+
+            callback({
+                ok: true,
+                msg: "Added Successfully.",
+            });
+
+        } catch (e) {
+            callback({
+                ok: false,
+                msg: e.message,
+            });
+        }
+    });
+
+    // Add a new monitor_maintenance
+    socket.on("addMaintenanceStatusPage", async (maintenanceID, statusPages, callback) => {
+        try {
+            checkLogin(socket);
+
+            await R.exec("DELETE FROM maintenance_status_page WHERE maintenance_id = ?", [
+                maintenanceID
+            ]);
+
+            for await (const statusPage of statusPages) {
+                let bean = R.dispense("maintenance_status_page");
+
+                bean.import({
+                    status_page_id: statusPage.id,
+                    maintenance_id: maintenanceID
+                });
+                await R.store(bean);
+            }
+
+            apicache.clear();
+
+            callback({
+                ok: true,
+                msg: "Added Successfully.",
+            });
+
+        } catch (e) {
+            callback({
+                ok: false,
+                msg: e.message,
+            });
+        }
+    });
+
+    socket.on("getMaintenance", async (maintenanceID, callback) => {
+        try {
+            checkLogin(socket);
+
+            log.debug("maintenance", `Get Maintenance: ${maintenanceID} User ID: ${socket.userID}`);
+
+            let bean = await R.findOne("maintenance", " id = ? AND user_id = ? ", [
+                maintenanceID,
+                socket.userID,
+            ]);
+
+            callback({
+                ok: true,
+                maintenance: await bean.toJSON(),
+            });
+
+        } catch (e) {
+            callback({
+                ok: false,
+                msg: e.message,
+            });
+        }
+    });
+
+    socket.on("getMaintenanceList", async (callback) => {
+        try {
+            checkLogin(socket);
+            await server.sendMaintenanceList(socket);
+            callback({
+                ok: true,
+            });
+        } catch (e) {
+            console.error(e);
+            callback({
+                ok: false,
+                msg: e.message,
+            });
+        }
+    });
+
+    socket.on("getMonitorMaintenance", async (maintenanceID, callback) => {
+        try {
+            checkLogin(socket);
+
+            log.debug("maintenance", `Get Monitors for Maintenance: ${maintenanceID} User ID: ${socket.userID}`);
+
+            let monitors = await R.getAll("SELECT monitor.id, monitor.name FROM monitor_maintenance mm JOIN monitor ON mm.monitor_id = monitor.id WHERE mm.maintenance_id = ? ", [
+                maintenanceID,
+            ]);
+
+            callback({
+                ok: true,
+                monitors,
+            });
+
+        } catch (e) {
+            console.error(e);
+            callback({
+                ok: false,
+                msg: e.message,
+            });
+        }
+    });
+
+    socket.on("getMaintenanceStatusPage", async (maintenanceID, callback) => {
+        try {
+            checkLogin(socket);
+
+            log.debug("maintenance", `Get Status Pages for Maintenance: ${maintenanceID} User ID: ${socket.userID}`);
+
+            let statusPages = await R.getAll("SELECT status_page.id, status_page.title FROM maintenance_status_page msp JOIN status_page ON msp.status_page_id = status_page.id WHERE msp.maintenance_id = ? ", [
+                maintenanceID,
+            ]);
+
+            callback({
+                ok: true,
+                statusPages,
+            });
+
+        } catch (e) {
+            console.error(e);
+            callback({
+                ok: false,
+                msg: e.message,
+            });
+        }
+    });
+
+    socket.on("deleteMaintenance", async (maintenanceID, callback) => {
+        try {
+            checkLogin(socket);
+
+            log.debug("maintenance", `Delete Maintenance: ${maintenanceID} User ID: ${socket.userID}`);
+
+            if (maintenanceID in server.maintenanceList) {
+                delete server.maintenanceList[maintenanceID];
+            }
+
+            await R.exec("DELETE FROM maintenance WHERE id = ? AND user_id = ? ", [
+                maintenanceID,
+                socket.userID,
+            ]);
+
+            callback({
+                ok: true,
+                msg: "Deleted Successfully.",
+            });
+
+            await server.sendMaintenanceList(socket);
+
+        } catch (e) {
+            callback({
+                ok: false,
+                msg: e.message,
+            });
+        }
+    });
+
+    socket.on("pauseMaintenance", async (maintenanceID, callback) => {
+        try {
+            checkLogin(socket);
+
+            log.debug("maintenance", `Pause Maintenance: ${maintenanceID} User ID: ${socket.userID}`);
+
+            await R.exec("UPDATE maintenance SET active = 0 WHERE id = ? ", [
+                maintenanceID,
+            ]);
+
+            callback({
+                ok: true,
+                msg: "Paused Successfully.",
+            });
+
+            await server.sendMaintenanceList(socket);
+
+        } catch (e) {
+            callback({
+                ok: false,
+                msg: e.message,
+            });
+        }
+    });
+
+    socket.on("resumeMaintenance", async (maintenanceID, callback) => {
+        try {
+            checkLogin(socket);
+
+            log.debug("maintenance", `Resume Maintenance: ${maintenanceID} User ID: ${socket.userID}`);
+
+            await R.exec("UPDATE maintenance SET active = 1 WHERE id = ? ", [
+                maintenanceID,
+            ]);
+
+            callback({
+                ok: true,
+                msg: "Resume Successfully",
+            });
+
+            await server.sendMaintenanceList(socket);
+
+        } catch (e) {
+            callback({
+                ok: false,
+                msg: e.message,
+            });
+        }
+    });
+};
--- a/server/uptime-kuma-server.js
+++ b/server/uptime-kuma-server.js
@ -9,6 +9,8 @@ const Database = require("./database");
 const util = require("util");
 const { CacheableDnsHttpAgent } = require("./cacheable-dns-http-agent");
 const { Settings } = require("./settings");
+const dayjs = require("dayjs");
+// DO NOT IMPORT HERE IF THE MODULES USED `UptimeKumaServer.getInstance()`

 /**
 * `module.exports` (alias: `server`) should be inside this class, in order to avoid circular dependency issue.
@ -26,6 +28,13 @@ class UptimeKumaServer {
     * @type {{}}
     */
    monitorList = {};
+
+    /**
+     * Main maintenance list
+     * @type {{}}
+     */
+    maintenanceList = {};
+
    entryPage = "dashboard";
    app = undefined;
    httpServer = undefined;
@ -37,6 +46,8 @@ class UptimeKumaServer {
     */
    indexHTML = "";

+    generateMaintenanceTimeslotsInterval = undefined;
+
    static getInstance(args) {
        if (UptimeKumaServer.instance == null) {
            UptimeKumaServer.instance = new UptimeKumaServer(args);
@ -77,6 +88,16 @@ class UptimeKumaServer {
        this.io = new Server(this.httpServer);
    }

+    async initAfterDatabaseReady() {
+        process.env.TZ = await this.getTimezone();
+        dayjs.tz.setDefault(process.env.TZ);
+        log.debug("DEBUG", "Timezone: " + process.env.TZ);
+        log.debug("DEBUG", "Current Time: " + dayjs.tz().format());
+
+        await this.generateMaintenanceTimeslots();
+        this.generateMaintenanceTimeslotsInterval = setInterval(this.generateMaintenanceTimeslots, 60 * 1000);
+    }
+
    async sendMonitorList(socket) {
        let list = await this.getMonitorJSONList(socket.userID);
        this.io.to(socket.userID).emit("monitorList", list);
@ -104,6 +125,40 @@ class UptimeKumaServer {
        return result;
    }

+    /**
+     * Send maintenance list to client
+     * @param {Socket} socket Socket.io instance to send to
+     * @returns {Object}
+     */
+    async sendMaintenanceList(socket) {
+        return await this.sendMaintenanceListByUserID(socket.userID);
+    }
+
+    async sendMaintenanceListByUserID(userID) {
+        let list = await this.getMaintenanceJSONList(userID);
+        this.io.to(userID).emit("maintenanceList", list);
+        return list;
+    }
+
+    /**
+     * Get a list of maintenances for the given user.
+     * @param {string} userID - The ID of the user to get maintenances for.
+     * @returns {Promise<Object>} A promise that resolves to an object with maintenance IDs as keys and maintenances objects as values.
+     */
+    async getMaintenanceJSONList(userID) {
+        let result = {};
+
+        let maintenanceList = await R.find("maintenance", " user_id = ? ORDER BY end_date DESC, title", [
+            userID,
+        ]);
+
+        for (let maintenance of maintenanceList) {
+            result[maintenance.id] = await maintenance.toJSON();
+        }
+
+        return result;
+    }
+
    /**
     * Write error to log file
     * @param {any} error The error to write
@ -147,8 +202,49 @@ class UptimeKumaServer {
            return clientIP.replace(/^.*:/, "");
        }
    }
+
+    async getTimezone() {
+        let timezone = await Settings.get("serverTimezone");
+        if (timezone) {
+            return timezone;
+        } else if (process.env.TZ) {
+            return process.env.TZ;
+        } else {
+            return dayjs.tz.guess();
+        }
+    }
+
+    getTimezoneOffset() {
+        return dayjs().format("Z");
+    }
+
+    async setTimezone(timezone) {
+        await Settings.set("serverTimezone", timezone, "general");
+        process.env.TZ = timezone;
+        dayjs.tz.setDefault(timezone);
+    }
+
+    async generateMaintenanceTimeslots() {
+
+        let list = await R.find("maintenance_timeslot", " generated_next = 0 AND start_date <= DATETIME('now') ");
+
+        for (let maintenanceTimeslot of list) {
+            let maintenance = await maintenanceTimeslot.maintenance;
+            await MaintenanceTimeslot.generateTimeslot(maintenance, maintenanceTimeslot.end_date, false);
+            maintenanceTimeslot.generated_next = true;
+            await R.store(maintenanceTimeslot);
+        }
+
+    }
+
+    async stop() {
+        clearTimeout(this.generateMaintenanceTimeslotsInterval);
+    }
 }

 module.exports = {
    UptimeKumaServer
 };
+
+// Must be at the end
+const MaintenanceTimeslot = require("./model/maintenance_timeslot");
--- a/server/util-server.js
+++ b/server/util-server.js
@ -21,6 +21,7 @@ const {
        rfc2865: { file, attributes },
    },
 } = require("node-radius-utils");
+const dayjs = require("dayjs");

 // From ping-lite
 exports.WIN = /^win/.test(process.platform);
@ -658,3 +659,64 @@ module.exports.send403 = (res, msg = "") => {
        "msg": msg,
    });
 };
+
+function timeObjectConvertTimezone(obj, timezone, timeObjectToUTC = true) {
+    let offsetString;
+
+    if (timezone) {
+        offsetString = dayjs().tz(timezone).format("Z");
+    } else {
+        offsetString = dayjs().format("Z");
+    }
+
+    let hours = parseInt(offsetString.substring(1, 3));
+    let minutes = parseInt(offsetString.substring(4, 6));
+
+    if (
+        (timeObjectToUTC && offsetString.startsWith("+")) ||
+        (!timeObjectToUTC && offsetString.startsWith("-"))
+    ) {
+        hours *= -1;
+        minutes *= -1;
+    }
+
+    obj.hours += hours;
+    obj.minutes += minutes;
+
+    // Handle out of bound
+    if (obj.minutes < 0) {
+        obj.minutes += 60;
+        obj.hours--;
+    } else if (obj.minutes > 60) {
+        obj.minutes -= 60;
+        obj.hours++;
+    }
+
+    if (obj.hours < 0) {
+        obj.hours += 24;
+    } else if (obj.hours > 24) {
+        obj.hours -= 24;
+    }
+
+    return obj;
+}
+
+/**
+ *
+ * @param {object} obj
+ * @param {string} timezone
+ * @returns {object}
+ */
+module.exports.timeObjectToUTC = (obj, timezone = undefined) => {
+    return timeObjectConvertTimezone(obj, timezone, true);
+};
+
+/**
+ *
+ * @param {object} obj
+ * @param {string} timezone
+ * @returns {object}
+ */
+module.exports.timeObjectToLocal = (obj, timezone = undefined) => {
+    return timeObjectConvertTimezone(obj, timezone, false);
+};
--- a/src/assets/app.scss
+++ b/src/assets/app.scss
@ -22,6 +22,19 @@ textarea.form-control {
    width: 10px;
 }

+.bg-maintenance {
+    color: white !important;
+    background-color: $maintenance !important;
+}
+
+.bg-dark {
+    color: white;
+}
+
+.text-maintenance {
+    color: $maintenance !important;
+}
+
 .list-group {
    border-radius: 0.75rem;

@ -107,6 +120,19 @@ optgroup {
    }
 }

+.btn-normal {
+    $bg-color: #F5F5F5;
+
+    background-color: $bg-color;
+    border-color: $bg-color;
+
+    &:hover {
+        $hover-color: darken($bg-color, 3%);
+        background-color: $hover-color;
+        border-color: $hover-color;
+    }
+}
+
 .btn-warning {
    color: white;

@ -256,6 +282,20 @@ optgroup {
        color: white;
    }

+    .btn-normal {
+        $bg-color: $dark-header-bg;
+
+        color: $dark-font-color;
+        background-color: $bg-color;
+        border-color: $bg-color;
+
+        &:hover {
+            $hover-color: darken($bg-color, 3%);
+            background-color: $hover-color;
+            border-color: $hover-color;
+        }
+    }
+
    .btn-warning {
        color: $dark-font-color2;

@ -323,6 +363,7 @@ optgroup {
        &.bg-info,
        &.bg-warning,
        &.bg-danger,
+        &.bg-maintenance,
        &.bg-light {
            color: $dark-font-color2;
        }
--- a/src/assets/vars.scss
+++ b/src/assets/vars.scss
@ -1,6 +1,7 @@
 $primary: #5cdd8b;
 $danger: #dc3545;
 $warning: #f8a306;
+$maintenance: #1747f5;
 $link-color: #111;
 $border-radius: 50rem;

--- a/src/assets/vue-datepicker.scss
+++ b/src/assets/vue-datepicker.scss
@ -0,0 +1,39 @@
+@import "@vuepic/vue-datepicker/dist/main.css";
+@import "vars.scss";
+
+// Must use #{ }
+// Remark: https://stackoverflow.com/questions/50202991/unable-to-set-scss-variable-to-css-variable
+.dp__theme_dark {
+    --dp-background-color: #{$dark-bg2};
+    --dp-text-color: #{$dark-font-color};
+    --dp-hover-color: #484848;
+    --dp-hover-text-color: #ffffff;
+    --dp-hover-icon-color: #959595;
+    --dp-primary-color: #{#5cdd8b};
+    --dp-primary-text-color: #ffffff;
+    --dp-secondary-color: #494949;
+    --dp-border-color: #{$dark-border-color};
+    --dp-menu-border-color: #2d2d2d;
+    --dp-border-color-hover: #{$dark-border-color};
+    --dp-disabled-color: #212121;
+    --dp-scroll-bar-background: #212121;
+    --dp-scroll-bar-color: #484848;
+    --dp-success-color: #{$primary};
+    --dp-success-color-disabled: #428f59;
+    --dp-icon-color: #959595;
+    --dp-danger-color: #e53935;
+    --dp-highlight-color: rgba(0, 92, 178, 0.2);
+}
+
+.dp__input {
+    border-radius: $border-radius;
+}
+
+// Fix: Full width of text input when using "inline textInput inlineWithInput" mode
+.dp__main > div[aria-label="Datepicker input"] {
+    width: 100%;
+}
+
+.dp__main > div[aria-label="Datepicker menu"]:nth-child(2) {
+    margin-top: 20px;
+}
--- a/src/components/Datetime.vue
+++ b/src/components/Datetime.vue
@ -4,12 +4,6 @@

 <script>
 import dayjs from "dayjs";
-import relativeTime from "dayjs/plugin/relativeTime";
-import timezone from "dayjs/plugin/timezone"; // dependent on utc plugin
-import utc from "dayjs/plugin/utc";
-dayjs.extend(utc);
-dayjs.extend(timezone);
-dayjs.extend(relativeTime);

 export default {
    props: {
--- a/src/components/HeartbeatBar.vue
+++ b/src/components/HeartbeatBar.vue
@ -5,7 +5,7 @@
                v-for="(beat, index) in shortBeatList"
                :key="index"
                class="beat"
-                :class="{ 'empty' : (beat === 0), 'down' : (beat.status === 0), 'pending' : (beat.status === 2) }"
+                :class="{ 'empty' : (beat === 0), 'down' : (beat.status === 0), 'pending' : (beat.status === 2), 'maintenance' : (beat.status === 3) }"
                :style="beatStyle"
                :title="getBeatTitle(beat)"
            />
@ -211,6 +211,10 @@ export default {
            background-color: $warning;
        }

+        &.maintenance {
+            background-color: $maintenance;
+        }
+
        &:not(.empty):hover {
            transition: all ease-in-out 0.15s;
            opacity: 0.8;
--- a/src/components/MaintenanceTime.vue
+++ b/src/components/MaintenanceTime.vue
@ -0,0 +1,44 @@
+<template>
+    <div>
+        <div v-if="maintenance.strategy === 'manual'" class="timeslot">
+            {{ $t("Manual") }}
+        </div>
+        <div v-else-if="maintenance.timeslotList.length > 0" class="timeslot">
+            {{ maintenance.timeslotList[0].startDateServerTimezone }}
+            <span class="to">-</span>
+            {{ maintenance.timeslotList[0].endDateServerTimezone }}
+            (UTC{{ maintenance.timeslotList[0].serverTimezoneOffset }})
+        </div>
+    </div>
+</template>
+
+<script>
+export default {
+    props: {
+        maintenance: {
+            type: Object,
+            required: true
+        },
+    },
+};
+</script>
+
+<style lang="scss">
+.timeslot {
+    margin-top: 5px;
+    display: inline-block;
+    font-size: 14px;
+    background-color: rgba(255, 255, 255, 0.5);
+    border-radius: 20px;
+    padding: 0 10px;
+
+    .to {
+        margin: 0 6px;
+    }
+
+    .dark & {
+        color: white;
+        background-color: rgba(255, 255, 255, 0.1);
+    }
+}
+</style>
--- a/src/components/PingChart.vue
+++ b/src/components/PingChart.vue
@ -16,18 +16,14 @@
    </div>
 </template>

-<script lang="ts">
+<script lang="js">
 import { BarController, BarElement, Chart, Filler, LinearScale, LineController, LineElement, PointElement, TimeScale, Tooltip } from "chart.js";
 import "chartjs-adapter-dayjs";
 import dayjs from "dayjs";
-import timezone from "dayjs/plugin/timezone";
-import utc from "dayjs/plugin/utc";
 import { LineChart } from "vue-chart-3";
 import { useToast } from "vue-toastification";
-import { DOWN, log } from "../util.ts";
+import { DOWN, PENDING, MAINTENANCE, log } from "../util.ts";

-dayjs.extend(utc);
-dayjs.extend(timezone);
 const toast = useToast();

 Chart.register(LineController, BarController, LineElement, PointElement, TimeScale, BarElement, LinearScale, Tooltip, Filler);
@ -163,7 +159,8 @@ export default {
        },
        chartData() {
            let pingData = [];  // Ping Data for Line Chart, y-axis contains ping time
-            let downData = [];  // Down Data for Bar Chart, y-axis is 1 if target is down, 0 if target is up
+            let downData = [];  // Down Data for Bar Chart, y-axis is 1 if target is down (red color), under maintenance (blue color) or pending (orange color), 0 if target is up
+            let colorData = []; // Color Data for Bar Chart

            let heartbeatList = this.heartbeatList ||
             (this.monitorId in this.$root.heartbeatList && this.$root.heartbeatList[this.monitorId]) ||
@ -185,8 +182,9 @@ export default {
                    });
                    downData.push({
                        x,
-                        y: beat.status === DOWN ? 1 : 0,
+                        y: (beat.status === DOWN || beat.status === MAINTENANCE || beat.status === PENDING) ? 1 : 0,
                    });
+                    colorData.push((beat.status === MAINTENANCE) ? "rgba(23,71,245,0.41)" : ((beat.status === PENDING) ? "rgba(245,182,23,0.41)" : "#DC354568"));
                });

            return {
@ -205,7 +203,7 @@ export default {
                        type: "bar",
                        data: downData,
                        borderColor: "#00000000",
-                        backgroundColor: "#DC354568",
+                        backgroundColor: colorData,
                        yAxisID: "y1",
                        barThickness: "flex",
                        barPercentage: 1,
--- a/src/components/PublicGroupList.vue
+++ b/src/components/PublicGroupList.vue
@ -225,4 +225,8 @@ export default {
    }
 }

+.bg-maintenance {
+    background-color: $maintenance;
+}
+
 </style>
--- a/src/components/Status.vue
+++ b/src/components/Status.vue
@ -26,6 +26,10 @@ export default {
                return "warning";
            }

+            if (this.status === 3) {
+                return "maintenance";
+            }
+
            return "secondary";
        },

@ -42,6 +46,10 @@ export default {
                return this.$t("Pending");
            }

+            if (this.status === 3) {
+                return this.$t("statusMaintenance");
+            }
+
            return this.$t("Unknown");
        },
    },
--- a/src/components/Uptime.vue
+++ b/src/components/Uptime.vue
@ -25,6 +25,10 @@ export default {
    computed: {
        uptime() {

+            if (this.type === "maintenance") {
+                return this.$t("statusMaintenance");
+            }
+
            let key = this.monitor.id + "_" + this.type;

            if (this.$root.uptimeList[key] !== undefined) {
@ -35,6 +39,10 @@ export default {
        },

        color() {
+            if (this.type === "maintenance" || this.monitor.maintenance) {
+                return "maintenance";
+            }
+
            if (this.lastHeartBeat.status === 0) {
                return "danger";
            }
--- a/src/components/settings/General.vue
+++ b/src/components/settings/General.vue
@ -1,10 +1,10 @@
 <template>
    <div>
        <form class="my-4" autocomplete="off" @submit.prevent="saveGeneral">
-            <!-- Timezone -->
+            <!-- Client side Timezone -->
            <div class="mb-4">
                <label for="timezone" class="form-label">
-                    {{ $t("Timezone") }}
+                    {{ $t("Display Timezone") }}
                </label>
                <select id="timezone" v-model="$root.userTimezone" class="form-select">
                    <option value="auto">
@ -20,6 +20,23 @@
                </select>
            </div>

+            <!-- Server Timezone -->
+            <div class="mb-4">
+                <label for="timezone" class="form-label">
+                    {{ $t("Server Timezone") }}
+                </label>
+                <select id="timezone" v-model="settings.serverTimezone" class="form-select">
+                    <option value="UTC">UTC</option>
+                    <option
+                        v-for="(timezone, index) in timezoneList"
+                        :key="index"
+                        :value="timezone.value"
+                    >
+                        {{ timezone.name }}
+                    </option>
+                </select>
+            </div>
+
            <!-- Search Engine -->
            <div class="mb-4">
                <label class="form-label">
@ -146,11 +163,7 @@
 <script>
 import HiddenInput from "../../components/HiddenInput.vue";
 import dayjs from "dayjs";
-import utc from "dayjs/plugin/utc";
-import timezone from "dayjs/plugin/timezone";
 import { timezoneList } from "../../util-frontend";
-dayjs.extend(utc);
-dayjs.extend(timezone);

 export default {
    components: {
--- a/src/icon.js
+++ b/src/icon.js
@ -41,6 +41,9 @@ import {
    faUndo,
    faPlusCircle,
    faAngleDown,
+    faWrench,
+    faHeartbeat,
+    faFilter,
 } from "@fortawesome/free-solid-svg-icons";

 library.add(
@ -82,6 +85,9 @@ library.add(
    faPlusCircle,
    faAngleDown,
    faLink,
+    faWrench,
+    faHeartbeat,
+    faFilter,
 );

 export { FontAwesomeIcon };
--- a/src/languages/en.js
+++ b/src/languages/en.js
@ -9,11 +9,24 @@ export default {
    upsideDownModeDescription: "Flip the status upside down. If the service is reachable, it is DOWN.",
    maxRedirectDescription: "Maximum number of redirects to follow. Set to 0 to disable redirects.",
    acceptedStatusCodesDescription: "Select status codes which are considered as a successful response.",
+    Maintenance: "Maintenance",
+    statusMaintenance: "Maintenance",
+    "Schedule maintenance": "Schedule maintenance",
+    "Affected Monitors": "Affected Monitors",
+    "Pick Affected Monitors...": "Pick Affected Monitors...",
+    "Start of maintenance": "Start of maintenance",
+    "All Status Pages": "All Status Pages",
+    "Select status pages...": "Select status pages...",
+    recurringIntervalMessage: "Run once every day | Run once every {0} days",
+    affectedMonitorsDescription: "Select monitors that are affected by current maintenance",
+    affectedStatusPages: "Show this maintenance message on selected status pages",
+    atLeastOneMonitor: "Select at least one affected monitor",
    passwordNotMatchMsg: "The repeat password does not match.",
    notificationDescription: "Notifications must be assigned to a monitor to function.",
    keywordDescription: "Search keyword in plain HTML or JSON response. The search is case-sensitive.",
    pauseDashboardHome: "Pause",
    deleteMonitorMsg: "Are you sure want to delete this monitor?",
+    deleteMaintenanceMsg: "Are you sure want to delete this maintenance?",
    deleteNotificationMsg: "Are you sure want to delete this notification for all monitors?",
    dnsPortDescription: "DNS server port. Defaults to 53. You can change the port at any time.",
    resolverserverDescription: "Cloudflare is the default server. You can change the resolver server anytime.",
@ -590,4 +603,32 @@ export default {
    SMSManager: "SMSManager",
    "You can divide numbers with": "You can divide numbers with",
    "or": "or",
+    recurringInterval: "Interval",
+    "Recurring": "Recurring",
+    strategyManual: "Active/Inactive Manually",
+    warningTimezone: "It is using the server's timezone",
+    weekdayShortMon: "Mon",
+    weekdayShortTue: "Tue",
+    weekdayShortWed: "Wed",
+    weekdayShortThu: "Thu",
+    weekdayShortFri: "Fri",
+    weekdayShortSat: "Sat",
+    weekdayShortSun: "Sun",
+    dayOfWeek: "Day of Week",
+    dayOfMonth: "Day of Month",
+    lastDay: "Last Day",
+    lastDay1: "Last Day of Month",
+    lastDay2: "2nd Last Day of Month",
+    lastDay3: "3rd Last Day of Month",
+    lastDay4: "4th Last Day of Month",
+    "No Maintenance": "No Maintenance",
+    pauseMaintenanceMsg: "Are you sure want to pause?",
+    "maintenanceStatus-under-maintenance": "Under Maintenance",
+    "maintenanceStatus-inactive": "Inactive",
+    "maintenanceStatus-scheduled": "Scheduled",
+    "maintenanceStatus-ended": "Ended",
+    "maintenanceStatus-unknown": "Unknown",
+    "Display Timezone": "Display Timezone",
+    "Server Timezone": "Server Timezone",
+    statusPageMaintenanceEndDate: "End",
 };
--- a/src/languages/zh-HK.js
+++ b/src/languages/zh-HK.js
@ -380,4 +380,6 @@ export default {
    proxyDescription: "必須將代理伺服器指派給監測器才能運作。",
    enableProxyDescription: "此代理伺服器在啟用前不會在監測器上生效，您可以藉由控制啟用狀態來暫時對所有的監測器停用代理伺服器。",
    setAsDefaultProxyDescription: "預設情況下，新監測器將啟用此代理伺服器。您仍可分別停用各監測器的代理伺服器。",
+    Maintenance: "維護",
+    statusMaintenance: "維護中",
 };
--- a/src/layouts/Layout.vue
+++ b/src/layouts/Layout.vue
@ -37,19 +37,32 @@
                            <div class="profile-pic">{{ $root.usernameFirstChar }}</div>
                            <font-awesome-icon icon="angle-down" />
                        </div>
+
+                        <!-- Header's Dropdown Menu -->
                        <ul class="dropdown-menu">
+                            <!-- Username -->
                            <li>
                                <i18n-t v-if="$root.username != null" tag="span" keypath="signedInDisp" class="dropdown-item-text">
                                    <strong>{{ $root.username }}</strong>
                                </i18n-t>
                                <span v-if="$root.username == null" class="dropdown-item-text">{{ $t("signedInDispDisabled") }}</span>
                            </li>
+
                            <li><hr class="dropdown-divider"></li>
+
+                            <!-- Functions -->
                            <li>
-                                <router-link to="/settings" class="dropdown-item" :class="{ active: $route.path.includes('settings') }">
+                                <router-link to="/maintenance" class="dropdown-item" :class="{ active: $route.path.includes('manage-maintenance') }">
+                                    <font-awesome-icon icon="wrench" /> {{ $t("Maintenance") }}
+                                </router-link>
+                            </li>
+
+                            <li>
+                                <router-link to="/settings/general" class="dropdown-item" :class="{ active: $route.path.includes('settings') }">
                                    <font-awesome-icon icon="cog" /> {{ $t("Settings") }}
                                </router-link>
                            </li>
+
                            <li v-if="$root.loggedIn && $root.socket.token !== 'autoLogin'">
                                <button class="dropdown-item" @click="$root.logout">
                                    <font-awesome-icon icon="sign-out-alt" />
@ -304,5 +317,4 @@ main {
        background-color: $dark-bg;
    }
 }
-
 </style>
--- a/src/main.js
+++ b/src/main.js
@ -5,6 +5,7 @@ import Toast from "vue-toastification";
 import "vue-toastification/dist/index.css";
 import App from "./App.vue";
 import "./assets/app.scss";
+import "./assets/vue-datepicker.scss";
 import { i18n } from "./i18n";
 import { FontAwesomeIcon } from "./icon.js";
 import datetime from "./mixins/datetime";
@ -15,6 +16,13 @@ import theme from "./mixins/theme";
 import lang from "./mixins/lang";
 import { router } from "./router";
 import { appName } from "./util.ts";
+import dayjs from "dayjs";
+import timezone from "dayjs/plugin/timezone";
+import utc from "dayjs/plugin/utc";
+import relativeTime from "dayjs/plugin/relativeTime";
+dayjs.extend(utc);
+dayjs.extend(timezone);
+dayjs.extend(relativeTime);

 const app = createApp({
    mixins: [
--- a/src/mixins/datetime.js
+++ b/src/mixins/datetime.js
@ -1,10 +1,4 @@
 import dayjs from "dayjs";
-import relativeTime from "dayjs/plugin/relativeTime";
-import timezone from "dayjs/plugin/timezone";
-import utc from "dayjs/plugin/utc";
-dayjs.extend(utc);
-dayjs.extend(timezone);
-dayjs.extend(relativeTime);

 /**
 * DateTime Mixin
@ -18,6 +12,19 @@ export default {
    },

    methods: {
+        toUTC(value) {
+            return dayjs.tz(value, this.timezone).utc().format();
+        },
+
+        /**
+         * Used for <input type="datetime" />
+         * @param value
+         * @returns {string}
+         */
+        toDateTimeInputFormat(value) {
+            return this.datetimeFormat(value, "YYYY-MM-DDTHH:mm");
+        },
+
        /**
         * Return a given value in the format YYYY-MM-DD HH:mm:ss
         * @param {any} value Value to format as date time
@ -27,6 +34,17 @@ export default {
            return this.datetimeFormat(value, "YYYY-MM-DD HH:mm:ss");
        },

+        datetimeMaintenance(value) {
+            const inputDate = new Date(value);
+            const now = new Date(Date.now());
+
+            if (inputDate.getFullYear() === now.getUTCFullYear() && inputDate.getMonth() === now.getUTCMonth() && inputDate.getDay() === now.getUTCDay()) {
+                return this.datetimeFormat(value, "HH:mm");
+            } else {
+                return this.datetimeFormat(value, "YYYY-MM-DD HH:mm");
+            }
+        },
+
        /**
         * Return a given value in the format YYYY-MM-DD
         * @param {any} value  Value to format as date
@ -64,7 +82,7 @@ export default {
                return dayjs.utc(value).tz(this.timezone).format(format);
            }
            return "";
-        }
+        },
    },

    computed: {
--- a/src/mixins/socket.js
+++ b/src/mixins/socket.js
@ -33,6 +33,7 @@ export default {
            allowLoginDialog: false,        // Allowed to show login dialog, but "loggedIn" have to be true too. This exists because prevent the login dialog show 0.1s in first before the socket server auth-ed.
            loggedIn: false,
            monitorList: { },
+            maintenanceList: { },
            heartbeatList: { },
            importantHeartbeatList: { },
            avgPingList: { },
@ -129,6 +130,10 @@ export default {
                this.monitorList = data;
            });

+            socket.on("maintenanceList", (data) => {
+                this.maintenanceList = data;
+            });
+
            socket.on("notificationList", (data) => {
                this.notificationList = data;
            });
@ -445,6 +450,13 @@ export default {
            socket.emit("getMonitorList", callback);
        },

+        getMaintenanceList(callback) {
+            if (! callback) {
+                callback = () => { };
+            }
+            socket.emit("getMaintenanceList", callback);
+        },
+
        /**
         * Add a monitor
         * @param {Object} monitor Object representing monitor to add
@ -454,6 +466,26 @@ export default {
            socket.emit("add", monitor, callback);
        },

+        addMaintenance(maintenance, callback) {
+            socket.emit("addMaintenance", maintenance, callback);
+        },
+
+        addMonitorMaintenance(maintenanceID, monitors, callback) {
+            socket.emit("addMonitorMaintenance", maintenanceID, monitors, callback);
+        },
+
+        addMaintenanceStatusPage(maintenanceID, statusPages, callback) {
+            socket.emit("addMaintenanceStatusPage", maintenanceID, statusPages, callback);
+        },
+
+        getMonitorMaintenance(maintenanceID, callback) {
+            socket.emit("getMonitorMaintenance", maintenanceID, callback);
+        },
+
+        getMaintenanceStatusPage(maintenanceID, callback) {
+            socket.emit("getMaintenanceStatusPage", maintenanceID, callback);
+        },
+
        /**
         * Delete monitor by ID
         * @param {number} monitorID ID of monitor to delete
@ -463,6 +495,10 @@ export default {
            socket.emit("deleteMonitor", monitorID, callback);
        },

+        deleteMaintenance(maintenanceID, callback) {
+            socket.emit("deleteMaintenance", maintenanceID, callback);
+        },
+
        /** Clear the hearbeat list */
        clearData() {
            console.log("reset heartbeat list");
@ -550,7 +586,12 @@ export default {
            for (let monitorID in this.lastHeartbeatList) {
                let lastHeartBeat = this.lastHeartbeatList[monitorID];

-                if (! lastHeartBeat) {
+                if (this.monitorList[monitorID].maintenance) {
+                    result[monitorID] = {
+                        text: this.$t("statusMaintenance"),
+                        color: "maintenance",
+                    };
+                } else if (! lastHeartBeat) {
                    result[monitorID] = unknown;
                } else if (lastHeartBeat.status === 1) {
                    result[monitorID] = {
@ -579,6 +620,7 @@ export default {
            let result = {
                up: 0,
                down: 0,
+                maintenance: 0,
                unknown: 0,
                pause: 0,
            };
@ -587,7 +629,9 @@ export default {
                let beat = this.$root.lastHeartbeatList[monitorID];
                let monitor = this.$root.monitorList[monitorID];

-                if (monitor && ! monitor.active) {
+                if (monitor && monitor.maintenance) {
+                    result.maintenance++;
+                } else if (monitor && ! monitor.active) {
                    result.pause++;
                } else if (beat) {
                    if (beat.status === 1) {
--- a/src/mixins/theme.js
+++ b/src/mixins/theme.js
@ -46,6 +46,10 @@ export default {
                }
                return this.userTheme;
            }
+        },
+
+        isDark() {
+            return this.theme === "dark";
        }
    },

--- a/src/pages/Dashboard.vue
+++ b/src/pages/Dashboard.vue
@ -1,7 +1,7 @@
 <template>
    <div class="container-fluid">
        <div class="row">
-            <div v-if="! $root.isMobile" class="col-12 col-md-5 col-xl-4">
+            <div v-if="!$root.isMobile" class="col-12 col-md-5 col-xl-4">
                <div>
                    <router-link to="/add" class="btn btn-primary mb-3"><font-awesome-icon icon="plus" /> {{ $t("Add New Monitor") }}</router-link>
                </div>
--- a/src/pages/DashboardHome.vue
+++ b/src/pages/DashboardHome.vue
@ -15,6 +15,10 @@
                        <h3>{{ $t("Down") }}</h3>
                        <span class="num text-danger">{{ $root.stats.down }}</span>
                    </div>
+                    <div class="col">
+                        <h3>{{ $t("Maintenance") }}</h3>
+                        <span class="num text-maintenance">{{ $root.stats.maintenance }}</span>
+                    </div>
                    <div class="col">
                        <h3>{{ $t("Unknown") }}</h3>
                        <span class="num text-secondary">{{ $root.stats.unknown }}</span>
--- a/src/pages/EditMaintenance.vue
+++ b/src/pages/EditMaintenance.vue
@ -0,0 +1,534 @@
+<template>
+    <transition name="slide-fade" appear>
+        <div>
+            <h1 class="mb-3">{{ pageName }}</h1>
+            <form @submit.prevent="submit">
+                <div class="shadow-box">
+                    <div class="row">
+                        <div class="col-xl-10">
+                            <!-- Title -->
+                            <div class="mb-3">
+                                <label for="name" class="form-label">{{ $t("Title") }}</label>
+                                <input
+                                    id="name" v-model="maintenance.title" type="text" class="form-control"
+                                    required
+                                >
+                            </div>
+
+                            <!-- Description -->
+                            <div class="my-3">
+                                <label for="description" class="form-label">{{ $t("Description") }}</label>
+                                <textarea
+                                    id="description" v-model="maintenance.description" class="form-control"
+                                ></textarea>
+                            </div>
+
+                            <!-- Affected Monitors -->
+                            <h2 class="mt-5">{{ $t("Affected Monitors") }}</h2>
+                            {{ $t("affectedMonitorsDescription") }}
+
+                            <div class="my-3">
+                                <VueMultiselect
+                                    id="affected_monitors"
+                                    v-model="affectedMonitors"
+                                    :options="affectedMonitorsOptions"
+                                    track-by="id"
+                                    label="name"
+                                    :multiple="true"
+                                    :close-on-select="false"
+                                    :clear-on-select="false"
+                                    :preserve-search="true"
+                                    :placeholder="$t('Pick Affected Monitors...')"
+                                    :preselect-first="false"
+                                    :max-height="600"
+                                    :taggable="false"
+                                ></VueMultiselect>
+                            </div>
+
+                            <!-- Status pages to display maintenance info on -->
+                            <h2 class="mt-5">{{ $t("Status Pages") }}</h2>
+                            {{ $t("affectedStatusPages") }}
+
+                            <div class="my-3">
+                                <!-- Show on all pages -->
+                                <div class="form-check mb-2">
+                                    <input
+                                        id="show-on-all-pages" v-model="showOnAllPages" class="form-check-input"
+                                        type="checkbox"
+                                    >
+                                    <label class="form-check-label" for="show-powered-by">{{
+                                        $t("All Status Pages")
+                                    }}</label>
+                                </div>
+
+                                <div v-if="!showOnAllPages">
+                                    <VueMultiselect
+                                        id="selected_status_pages"
+                                        v-model="selectedStatusPages"
+                                        :options="selectedStatusPagesOptions"
+                                        track-by="id"
+                                        label="name"
+                                        :multiple="true"
+                                        :close-on-select="false"
+                                        :clear-on-select="false"
+                                        :preserve-search="true"
+                                        :placeholder="$t('Select status pages...')"
+                                        :preselect-first="false"
+                                        :max-height="600"
+                                        :taggable="false"
+                                    ></VueMultiselect>
+                                </div>
+                            </div>
+
+                            <h2 class="mt-5">{{ $t("Date and Time") }}</h2>
+
+                            <div>⚠️ {{ $t("warningTimezone") }}: <mark>{{ $root.info.serverTimezone }} ({{ $root.info.serverTimezoneOffset }})</mark></div>
+
+                            <!-- Strategy -->
+                            <div class="my-3">
+                                <label for="strategy" class="form-label">{{ $t("Strategy") }}</label>
+                                <select id="strategy" v-model="maintenance.strategy" class="form-select">
+                                    <option value="manual">{{ $t("strategyManual") }}</option>
+                                    <option value="single">Single Maintenance Window</option>
+                                    <option value="recurring-interval">{{ $t("Recurring") }} - {{ $t("recurringInterval") }}</option>
+                                    <option value="recurring-weekday">{{ $t("Recurring") }} - {{ $t("dayOfWeek") }}</option>
+                                    <option value="recurring-day-of-month">{{ $t("Recurring") }} - {{ $t("dayOfMonth") }}</option>
+                                    <option v-if="false" value="recurring-day-of-year">{{ $t("Recurring") }} - Day of Year</option>
+                                </select>
+                            </div>
+
+                            <!-- Single Maintenance Window -->
+                            <template v-if="maintenance.strategy === 'single'">
+                                <!-- DateTime Range -->
+                                <div class="my-3">
+                                    <label class="form-label">{{ $t("DateTime Range") }}</label>
+                                    <Datepicker
+                                        v-model="maintenance.dateRange"
+                                        :dark="$root.isDark"
+                                        range
+                                        :monthChangeOnScroll="false"
+                                        :minDate="minDate"
+                                        format="yyyy-MM-dd HH:mm"
+                                        modelType="yyyy-MM-dd HH:mm:ss"
+                                    />
+                                </div>
+                            </template>
+
+                            <!-- Recurring - Interval -->
+                            <template v-if="maintenance.strategy === 'recurring-interval'">
+                                <div class="my-3">
+                                    <label for="interval-day" class="form-label">
+                                        {{ $t("recurringInterval") }}
+
+                                        <template v-if="maintenance.intervalDay >= 1">
+                                            ({{
+                                                $tc("recurringIntervalMessage", maintenance.intervalDay, [
+                                                    maintenance.intervalDay
+                                                ])
+                                            }})
+                                        </template>
+                                    </label>
+                                    <input id="interval-day" v-model="maintenance.intervalDay" type="number" class="form-control" required min="1" max="3650" step="1">
+                                </div>
+                            </template>
+
+                            <!-- Recurring - Weekday -->
+                            <template v-if="maintenance.strategy === 'recurring-weekday'">
+                                <div class="my-3">
+                                    <label for="interval-day" class="form-label">
+                                        {{ $t("dayOfWeek") }}
+                                    </label>
+
+                                    <!-- Weekday Picker -->
+                                    <div class="weekday-picker">
+                                        <div v-for="(weekday, index) in weekdays" :key="index">
+                                            <label class="form-check-label" :for="weekday.id">{{ $t(weekday.langKey) }}</label>
+                                            <div class="form-check-inline"><input :id="weekday.id" v-model="maintenance.weekdays" type="checkbox" :value="weekday.value" class="form-check-input"></div>
+                                        </div>
+                                    </div>
+                                </div>
+                            </template>
+
+                            <!-- Recurring - Day of month -->
+                            <template v-if="maintenance.strategy === 'recurring-day-of-month'">
+                                <div class="my-3">
+                                    <label for="interval-day" class="form-label">
+                                        {{ $t("dayOfMonth") }}
+                                    </label>
+
+                                    <!-- Day Picker -->
+                                    <div class="day-picker">
+                                        <div v-for="index in 31" :key="index">
+                                            <label class="form-check-label" :for="'day' + index">{{ index }}</label>
+                                            <div class="form-check-inline">
+                                                <input :id="'day' + index" v-model="maintenance.daysOfMonth" type="checkbox" :value="index" class="form-check-input">
+                                            </div>
+                                        </div>
+                                    </div>
+
+                                    <div class="mt-3 mb-2">{{ $t("lastDay") }}</div>
+
+                                    <div v-for="(lastDay, index) in lastDays" :key="index" class="form-check">
+                                        <input :id="lastDay.langKey" v-model="maintenance.daysOfMonth" type="checkbox" :value="lastDay.value" class="form-check-input">
+                                        <label class="form-check-label" :for="lastDay.langKey">
+                                            {{ $t(lastDay.langKey) }}
+                                        </label>
+                                    </div>
+                                </div>
+                            </template>
+
+                            <!-- For any recurring types -->
+                            <template v-if="maintenance.strategy === 'recurring-interval' || maintenance.strategy === 'recurring-weekday' || maintenance.strategy === 'recurring-day-of-month'">
+                                <!-- Maintenance Time Window of a Day -->
+                                <div class="my-3">
+                                    <label class="form-label">{{ $t("Maintenance Time Window of a Day") }}</label>
+                                    <Datepicker
+                                        v-model="maintenance.timeRange"
+                                        :dark="$root.isDark"
+                                        timePicker
+                                        disableTimeRangeValidation range
+                                    />
+                                </div>
+
+                                <!-- Date Range -->
+                                <div class="my-3">
+                                    <label class="form-label">{{ $t("Effective Date Range") }}</label>
+                                    <Datepicker
+                                        v-model="maintenance.dateRange"
+                                        :dark="$root.isDark"
+                                        range datePicker
+                                        :monthChangeOnScroll="false"
+                                        :minDate="minDate"
+                                        format="yyyy-MM-dd HH:mm:ss"
+                                        modelType="yyyy-MM-dd HH:mm:ss"
+                                        required
+                                    />
+                                </div>
+                            </template>
+
+                            <div class="mt-4 mb-1">
+                                <button
+                                    id="monitor-submit-btn" class="btn btn-primary" type="submit"
+                                    :disabled="processing"
+                                >
+                                    {{ $t("Save") }}
+                                </button>
+                            </div>
+                        </div>
+                    </div>
+                </div>
+            </form>
+        </div>
+    </transition>
+</template>
+
+<script>
+
+import { useToast } from "vue-toastification";
+import VueMultiselect from "vue-multiselect";
+import dayjs from "dayjs";
+import Datepicker from "@vuepic/vue-datepicker";
+
+const toast = useToast();
+
+export default {
+    components: {
+        VueMultiselect,
+        Datepicker
+    },
+
+    data() {
+        return {
+            processing: false,
+            maintenance: {},
+            affectedMonitors: [],
+            affectedMonitorsOptions: [],
+            showOnAllPages: false,
+            selectedStatusPages: [],
+            dark: (this.$root.theme === "dark"),
+            neverEnd: false,
+            minDate: this.$root.date(dayjs()) + " 00:00",
+            lastDays: [
+                {
+                    langKey: "lastDay1",
+                    value: "lastDay1",
+                },
+                {
+                    langKey: "lastDay2",
+                    value: "lastDay2",
+                },
+                {
+                    langKey: "lastDay3",
+                    value: "lastDay3",
+                },
+                {
+                    langKey: "lastDay4",
+                    value: "lastDay4",
+                }
+            ],
+            weekdays: [
+                {
+                    id: "weekday1",
+                    langKey: "weekdayShortMon",
+                    value: 1,
+                },
+                {
+                    id: "weekday2",
+                    langKey: "weekdayShortTue",
+                    value: 2,
+                },
+                {
+                    id: "weekday3",
+                    langKey: "weekdayShortWed",
+                    value: 3,
+                },
+                {
+                    id: "weekday4",
+                    langKey: "weekdayShortTue",
+                    value: 4,
+                },
+                {
+                    id: "weekday5",
+                    langKey: "weekdayShortFri",
+                    value: 5,
+                },
+                {
+                    id: "weekday6",
+                    langKey: "weekdayShortSat",
+                    value: 6,
+                },
+                {
+                    id: "weekday0",
+                    langKey: "weekdayShortSun",
+                    value: 0,
+                },
+            ],
+        };
+    },
+
+    computed: {
+
+        selectedStatusPagesOptions() {
+            return Object.values(this.$root.statusPageList).map(statusPage => {
+                return {
+                    id: statusPage.id,
+                    name: statusPage.title
+                };
+            });
+        },
+
+        pageName() {
+            return this.$t((this.isAdd) ? "Schedule Maintenance" : "Edit Maintenance");
+        },
+
+        isAdd() {
+            return this.$route.path === "/add-maintenance";
+        },
+
+        isEdit() {
+            return this.$route.path.startsWith("/maintenance/edit");
+        },
+
+    },
+    watch: {
+        "$route.fullPath"() {
+            this.init();
+        },
+
+        neverEnd(value) {
+            if (value) {
+                this.maintenance.recurringEndDate = "";
+            }
+        },
+    },
+    mounted() {
+        this.init();
+
+        this.$root.getMonitorList((res) => {
+            if (res.ok) {
+                Object.values(this.$root.monitorList).map(monitor => {
+                    this.affectedMonitorsOptions.push({
+                        id: monitor.id,
+                        name: monitor.name,
+                    });
+                });
+            }
+        });
+    },
+    methods: {
+        init() {
+            this.affectedMonitors = [];
+            this.selectedStatusPages = [];
+
+            if (this.isAdd) {
+                this.maintenance = {
+                    title: "",
+                    description: "",
+                    strategy: "single",
+                    active: 1,
+                    intervalDay: 1,
+                    dateRange: [ this.minDate ],
+                    timeRange: [{
+                        hours: 2,
+                        minutes: 0,
+                    }, {
+                        hours: 3,
+                        minutes: 0,
+                    }],
+                    weekdays: [],
+                    daysOfMonth: [],
+                };
+            } else if (this.isEdit) {
+                this.$root.getSocket().emit("getMaintenance", this.$route.params.id, (res) => {
+                    if (res.ok) {
+                        this.maintenance = res.maintenance;
+
+                        this.$root.getSocket().emit("getMonitorMaintenance", this.$route.params.id, (res) => {
+                            if (res.ok) {
+                                Object.values(res.monitors).map(monitor => {
+                                    this.affectedMonitors.push(monitor);
+                                });
+                            } else {
+                                toast.error(res.msg);
+                            }
+                        });
+
+                        this.$root.getSocket().emit("getMaintenanceStatusPage", this.$route.params.id, (res) => {
+                            if (res.ok) {
+                                Object.values(res.statusPages).map(statusPage => {
+                                    this.selectedStatusPages.push({
+                                        id: statusPage.id,
+                                        name: statusPage.title
+                                    });
+                                });
+
+                                this.showOnAllPages = Object.values(res.statusPages).length === this.selectedStatusPagesOptions.length;
+                            } else {
+                                toast.error(res.msg);
+                            }
+                        });
+                    } else {
+                        toast.error(res.msg);
+                    }
+                });
+            }
+        },
+
+        async submit() {
+            this.processing = true;
+
+            if (this.affectedMonitors.length === 0) {
+                toast.error(this.$t("atLeastOneMonitor"));
+                return this.processing = false;
+            }
+
+            if (this.isAdd) {
+                this.$root.addMaintenance(this.maintenance, async (res) => {
+                    if (res.ok) {
+                        await this.addMonitorMaintenance(res.maintenanceID, async () => {
+                            await this.addMaintenanceStatusPage(res.maintenanceID, () => {
+                                toast.success(res.msg);
+                                this.processing = false;
+                                this.$root.getMaintenanceList();
+                                this.$router.push("/maintenance");
+                            });
+                        });
+                    } else {
+                        toast.error(res.msg);
+                        this.processing = false;
+                    }
+
+                });
+            } else {
+                this.$root.getSocket().emit("editMaintenance", this.maintenance, async (res) => {
+                    if (res.ok) {
+                        await this.addMonitorMaintenance(res.maintenanceID, async () => {
+                            await this.addMaintenanceStatusPage(res.maintenanceID, () => {
+                                this.processing = false;
+                                this.$root.toastRes(res);
+                                this.init();
+                                this.$router.push("/maintenance");
+                            });
+                        });
+                    } else {
+                        this.processing = false;
+                        toast.error(res.msg);
+                    }
+                });
+            }
+        },
+
+        async addMonitorMaintenance(maintenanceID, callback) {
+            await this.$root.addMonitorMaintenance(maintenanceID, this.affectedMonitors, async (res) => {
+                if (!res.ok) {
+                    toast.error(res.msg);
+                } else {
+                    this.$root.getMonitorList();
+                }
+
+                callback();
+            });
+        },
+
+        async addMaintenanceStatusPage(maintenanceID, callback) {
+            await this.$root.addMaintenanceStatusPage(maintenanceID, (this.showOnAllPages) ? this.selectedStatusPagesOptions : this.selectedStatusPages, async (res) => {
+                if (!res.ok) {
+                    toast.error(res.msg);
+                } else {
+                    this.$root.getMaintenanceList();
+                }
+
+                callback();
+            });
+        },
+    },
+};
+</script>
+
+<style lang="scss" scoped>
+.shadow-box {
+    padding: 20px;
+}
+
+textarea {
+    min-height: 150px;
+}
+
+.dark-calendar::-webkit-calendar-picker-indicator {
+    filter: invert(1);
+}
+
+.weekday-picker {
+    display: flex;
+    gap: 10px;
+
+    & > div {
+        display: flex;
+        flex-direction: column;
+        align-items: center;
+        width: 40px;
+
+        .form-check-inline {
+            margin-right: 0;
+        }
+    }
+}
+
+.day-picker {
+    display: flex;
+    gap: 10px;
+    flex-wrap: wrap;
+
+    & > div {
+        display: flex;
+        flex-direction: column;
+        align-items: center;
+        width: 40px;
+
+        .form-check-inline {
+            margin-right: 0;
+        }
+    }
+}
+
+</style>
--- a/src/pages/MaintenanceDetails.vue
+++ b/src/pages/MaintenanceDetails.vue
@ -0,0 +1,161 @@
+<template>
+    <transition name="slide-fade" appear>
+        <div v-if="maintenance">
+            <h1>{{ maintenance.title }}</h1>
+            <p class="url">
+                <span>{{ $t("Start") }}: {{ $root.datetimeMaintenance(maintenance.start_date) }}</span>
+                <br>
+                <span>{{ $t("End") }}: {{ $root.datetimeMaintenance(maintenance.end_date) }}</span>
+            </p>
+
+            <div class="functions" style="margin-top: 10px;">
+                <router-link :to=" '/maintenance/edit/' + maintenance.id " class="btn btn-secondary">
+                    <font-awesome-icon icon="edit" /> {{ $t("Edit") }}
+                </router-link>
+                <button class="btn btn-danger" @click="deleteDialog">
+                    <font-awesome-icon icon="trash" /> {{ $t("Delete") }}
+                </button>
+            </div>
+
+            <label for="description" class="form-label" style="margin-top: 20px;">{{ $t("Description") }}</label>
+            <textarea id="description" v-model="maintenance.description" class="form-control" disabled></textarea>
+
+            <label for="affected_monitors" class="form-label" style="margin-top: 20px;">{{ $t("Affected Monitors") }}</label>
+            <br>
+            <button v-for="monitor in affectedMonitors" :key="monitor.id" class="btn btn-monitor" style="margin: 5px; cursor: auto; color: white; font-weight: 500;">
+                {{ monitor }}
+            </button>
+            <br />
+
+            <label for="selected_status_pages" class="form-label" style="margin-top: 20px;">{{ $t("Show this Maintenance Message on which Status Pages") }}</label>
+            <br>
+            <button v-for="statusPage in selectedStatusPages" :key="statusPage.id" class="btn btn-monitor" style="margin: 5px; cursor: auto; color: white; font-weight: 500;">
+                {{ statusPage }}
+            </button>
+
+            <Confirm ref="confirmDelete" btn-style="btn-danger" :yes-text="$t('Yes')" :no-text="$t('No')" @yes="deleteMaintenance">
+                {{ $t("deleteMaintenanceMsg") }}
+            </Confirm>
+        </div>
+    </transition>
+</template>
+
+<script>
+import { useToast } from "vue-toastification";
+const toast = useToast();
+import Confirm from "../components/Confirm.vue";
+
+export default {
+    components: {
+        Confirm,
+    },
+    data() {
+        return {
+            affectedMonitors: [],
+            selectedStatusPages: [],
+        };
+    },
+    computed: {
+        maintenance() {
+            let id = this.$route.params.id;
+            return this.$root.maintenanceList[id];
+        },
+    },
+    mounted() {
+        this.init();
+    },
+    methods: {
+        init() {
+            this.$root.getSocket().emit("getMonitorMaintenance", this.$route.params.id, (res) => {
+                if (res.ok) {
+                    this.affectedMonitors = Object.values(res.monitors).map(monitor => monitor.name);
+                } else {
+                    toast.error(res.msg);
+                }
+            });
+
+            this.$root.getSocket().emit("getMaintenanceStatusPage", this.$route.params.id, (res) => {
+                if (res.ok) {
+                    this.selectedStatusPages = Object.values(res.statusPages).map(statusPage => statusPage.title);
+                } else {
+                    toast.error(res.msg);
+                }
+            });
+        },
+
+        deleteDialog() {
+            this.$refs.confirmDelete.show();
+        },
+
+        deleteMaintenance() {
+            this.$root.deleteMaintenance(this.maintenance.id, (res) => {
+                if (res.ok) {
+                    toast.success(res.msg);
+                    this.$router.push("/maintenance");
+                } else {
+                    toast.error(res.msg);
+                }
+            });
+        },
+    },
+};
+</script>
+
+<style lang="scss" scoped>
+@import "../assets/vars.scss";
+
+@media (max-width: 550px) {
+    .functions {
+        text-align: center;
+
+        button, a {
+            margin-left: 10px !important;
+            margin-right: 10px !important;
+        }
+    }
+}
+
+@media (max-width: 400px) {
+    .btn {
+        display: inline-flex;
+        flex-direction: column;
+        align-items: center;
+        padding-top: 10px;
+    }
+
+    a.btn {
+        padding-left: 25px;
+        padding-right: 25px;
+    }
+}
+
+.url {
+    color: $primary;
+    margin-bottom: 20px;
+    font-weight: bold;
+
+    a {
+        color: $primary;
+    }
+}
+
+.functions {
+    button, a {
+        margin-right: 20px;
+    }
+}
+
+textarea {
+    min-height: 100px;
+    resize: none;
+}
+
+.btn-monitor {
+    background-color: #5cdd8b;
+}
+
+.dark .btn-monitor {
+    color: #020b05 !important;
+}
+
+</style>
--- a/src/pages/ManageMaintenance.vue
+++ b/src/pages/ManageMaintenance.vue
@ -0,0 +1,280 @@
+<template>
+    <transition name="slide-fade" appear>
+        <div>
+            <h1 class="mb-3">
+                {{ $t("Maintenance") }}
+            </h1>
+
+            <div>
+                <router-link to="/add-maintenance" class="btn btn-primary mb-3">
+                    <font-awesome-icon icon="plus" /> {{ $t("Schedule Maintenance") }}
+                </router-link>
+            </div>
+
+            <div class="shadow-box">
+                <span v-if="Object.keys(sortedMaintenanceList).length === 0" class="d-flex align-items-center justify-content-center my-3">
+                    {{ $t("No Maintenance") }}
+                </span>
+
+                <div
+                    v-for="(item, index) in sortedMaintenanceList"
+                    :key="index"
+                    class="item"
+                    :class="item.status"
+                >
+                    <div class="left-part">
+                        <div
+                            class="circle"
+                        ></div>
+                        <div class="info">
+                            <div class="title">{{ item.title }}</div>
+                            <div v-if="false">{{ item.description }}</div>
+                            <div class="status">
+                                {{ $t("maintenanceStatus-" + item.status) }}
+                            </div>
+
+                            <MaintenanceTime :maintenance="item" />
+                        </div>
+                    </div>
+
+                    <div class="buttons">
+                        <router-link v-if="false" :to="maintenanceURL(item.id)" class="btn btn-light">{{ $t("Details") }}</router-link>
+
+                        <div class="btn-group" role="group">
+                            <button v-if="item.active" class="btn btn-normal" @click="pauseDialog(item.id)">
+                                <font-awesome-icon icon="pause" /> {{ $t("Pause") }}
+                            </button>
+
+                            <button v-if="!item.active" class="btn btn-primary" @click="resumeMaintenance(item.id)">
+                                <font-awesome-icon icon="play" /> {{ $t("Resume") }}
+                            </button>
+
+                            <router-link :to="'/maintenance/edit/' + item.id" class="btn btn-normal">
+                                <font-awesome-icon icon="edit" /> {{ $t("Edit") }}
+                            </router-link>
+
+                            <button class="btn btn-danger" @click="deleteDialog(item.id)">
+                                <font-awesome-icon icon="trash" /> {{ $t("Delete") }}
+                            </button>
+                        </div>
+                    </div>
+                </div>
+            </div>
+
+            <div class="text-center mt-3" style="font-size: 13px;">
+                <a href="https://github.com/louislam/uptime-kuma/wiki/Maintenance" target="_blank">Learn More</a>
+            </div>
+
+            <Confirm ref="confirmPause" :yes-text="$t('Yes')" :no-text="$t('No')" @yes="pauseMaintenance">
+                {{ $t("pauseMaintenanceMsg") }}
+            </Confirm>
+
+            <Confirm ref="confirmDelete" btn-style="btn-danger" :yes-text="$t('Yes')" :no-text="$t('No')" @yes="deleteMaintenance">
+                {{ $t("deleteMaintenanceMsg") }}
+            </Confirm>
+        </div>
+    </transition>
+</template>
+
+<script>
+import { getResBaseURL } from "../util-frontend";
+import { getMaintenanceRelativeURL } from "../util.ts";
+import Confirm from "../components/Confirm.vue";
+import MaintenanceTime from "../components/MaintenanceTime.vue";
+import { useToast } from "vue-toastification";
+const toast = useToast();
+
+export default {
+    components: {
+        MaintenanceTime,
+        Confirm,
+    },
+    data() {
+        return {
+            selectedMaintenanceID: undefined,
+            statusOrderList: {
+                "under-maintenance": 1000,
+                "scheduled": 900,
+                "inactive": 800,
+                "ended": 700,
+                "unknown": 0,
+            }
+        };
+    },
+    computed: {
+        sortedMaintenanceList() {
+            let result = Object.values(this.$root.maintenanceList);
+
+            result.sort((m1, m2) => {
+                if (this.statusOrderList[m1.status] === this.statusOrderList[m2.status]) {
+                    return m1.title.localeCompare(m2.title);
+                } else {
+                    return this.statusOrderList[m1.status] < this.statusOrderList[m2.status];
+                }
+            });
+
+            return result;
+        },
+    },
+    mounted() {
+
+    },
+    methods: {
+        /**
+         * Get the correct URL for the icon
+         * @param {string} icon Path for icon
+         * @returns {string} Correctly formatted path including port numbers
+         */
+        icon(icon) {
+            if (icon === "/icon.svg") {
+                return icon;
+            } else {
+                return getResBaseURL() + icon;
+            }
+        },
+
+        maintenanceURL(id) {
+            return getMaintenanceRelativeURL(id);
+        },
+
+        deleteDialog(maintenanceID) {
+            this.selectedMaintenanceID = maintenanceID;
+            this.$refs.confirmDelete.show();
+        },
+
+        deleteMaintenance() {
+            this.$root.deleteMaintenance(this.selectedMaintenanceID, (res) => {
+                if (res.ok) {
+                    toast.success(res.msg);
+                    this.$router.push("/maintenance");
+                } else {
+                    toast.error(res.msg);
+                }
+            });
+        },
+
+        /**
+         * Show dialog to confirm pause
+         */
+        pauseDialog(maintenanceID) {
+            this.selectedMaintenanceID = maintenanceID;
+            this.$refs.confirmPause.show();
+        },
+
+        /**
+         * Pause maintenance
+         */
+        pauseMaintenance() {
+            this.$root.getSocket().emit("pauseMaintenance", this.selectedMaintenanceID, (res) => {
+                this.$root.toastRes(res);
+            });
+        },
+
+        /**
+         * Resume maintenance
+         */
+        resumeMaintenance(id) {
+            this.$root.getSocket().emit("resumeMaintenance", id, (res) => {
+                this.$root.toastRes(res);
+            });
+        },
+    },
+};
+</script>
+
+<style lang="scss" scoped>
+    @import "../assets/vars.scss";
+
+    .item {
+        display: flex;
+        align-items: center;
+        gap: 10px;
+        text-decoration: none;
+        border-radius: 10px;
+        transition: all ease-in-out 0.15s;
+        justify-content: space-between;
+        padding: 10px;
+        min-height: 90px;
+        margin-bottom: 5px;
+
+        &:hover {
+            background-color: $highlight-white;
+        }
+
+        &.under-maintenance {
+            background-color: rgba(23, 71, 245, 0.16);
+
+            &:hover {
+                background-color: rgba(23, 71, 245, 0.3) !important;
+            }
+
+            .circle {
+                background-color: $maintenance;
+            }
+        }
+
+        &.scheduled {
+            .circle {
+                background-color: $primary;
+            }
+        }
+
+        &.inactive {
+            .circle {
+                background-color: $danger;
+            }
+        }
+
+        &.ended {
+            .left-part {
+                opacity: 0.3;
+            }
+
+            .circle {
+                background-color: $dark-font-color;
+            }
+        }
+
+        &.unknown {
+            .circle {
+                background-color: $dark-font-color;
+            }
+        }
+
+        .left-part {
+            display: flex;
+            gap: 12px;
+            align-items: center;
+
+            .circle {
+                width: 25px;
+                height: 25px;
+                border-radius: 50rem;
+            }
+
+            .info {
+                .title {
+                    font-weight: bold;
+                    font-size: 20px;
+                }
+
+                .status {
+                    font-size: 14px;
+                }
+            }
+        }
+
+        .buttons {
+            display: flex;
+            gap: 8px;
+        }
+    }
+
+    .dark {
+        .item {
+            &:hover {
+                background-color: $dark-bg2;
+            }
+        }
+    }
+</style>
--- a/src/pages/StatusPage.vue
+++ b/src/pages/StatusPage.vue
@ -218,12 +218,29 @@
                        {{ $t("Degraded Service") }}
                    </div>

+                    <div v-else-if="isMaintenance">
+                        <font-awesome-icon icon="wrench" class="status-maintenance" />
+                        {{ $t("maintenanceStatus-under-maintenance") }}
+                    </div>
+
                    <div v-else>
                        <font-awesome-icon icon="question-circle" style="color: #efefef;" />
                    </div>
                </template>
            </div>

+            <!-- Maintenance -->
+            <template v-if="maintenanceList.length > 0">
+                <div
+                    v-for="maintenance in maintenanceList" :key="maintenance.id"
+                    class="shadow-box alert mb-4 p-3 bg-maintenance mt-4 position-relative" role="alert"
+                >
+                    <h4 class="alert-heading">{{ maintenance.title }}</h4>
+                    <div class="content">{{ maintenance.description }}</div>
+                    <MaintenanceTime :maintenance="maintenance" />
+                </div>
+            </template>
+
            <!-- Description -->
            <strong v-if="editMode">{{ $t("Description") }}:</strong>
            <Editable v-model="config.description" :contenteditable="editMode" tag="div" class="mb-4 description" />
@ -295,8 +312,9 @@ import "vue-prism-editor/dist/prismeditor.min.css"; // import the styles somewhe
 import { useToast } from "vue-toastification";
 import Confirm from "../components/Confirm.vue";
 import PublicGroupList from "../components/PublicGroupList.vue";
+import MaintenanceTime from "../components/MaintenanceTime.vue";
 import { getResBaseURL } from "../util-frontend";
-import { STATUS_PAGE_ALL_DOWN, STATUS_PAGE_ALL_UP, STATUS_PAGE_PARTIAL_DOWN, UP } from "../util.ts";
+import { STATUS_PAGE_ALL_DOWN, STATUS_PAGE_ALL_UP, STATUS_PAGE_MAINTENANCE, STATUS_PAGE_PARTIAL_DOWN, UP, MAINTENANCE } from "../util.ts";

 const toast = useToast();

@ -316,6 +334,7 @@ export default {
        ImageCropUpload,
        Confirm,
        PrismEditor,
+        MaintenanceTime,
    },

    // Leave Page for vue route change
@ -356,6 +375,7 @@ export default {
            loadedData: false,
            baseURL: "",
            clickedEditButton: false,
+            maintenanceList: [],
        };
    },
    computed: {
@ -409,6 +429,10 @@ export default {
            return "bg-" + this.incident.style;
        },

+        maintenanceClass() {
+            return "bg-maintenance";
+        },
+
        overallStatus() {

            if (Object.keys(this.$root.publicLastHeartbeatList).length === 0) {
@ -421,7 +445,9 @@ export default {
            for (let id in this.$root.publicLastHeartbeatList) {
                let beat = this.$root.publicLastHeartbeatList[id];

-                if (beat.status === UP) {
+                if (beat.status === MAINTENANCE) {
+                    return STATUS_PAGE_MAINTENANCE;
+                } else if (beat.status === UP) {
                    hasUp = true;
                } else {
                    status = STATUS_PAGE_PARTIAL_DOWN;
@ -447,6 +473,10 @@ export default {
            return this.overallStatus === STATUS_PAGE_ALL_DOWN;
        },

+        isMaintenance() {
+            return this.overallStatus === STATUS_PAGE_MAINTENANCE;
+        },
+
    },
    watch: {

@ -551,6 +581,7 @@ export default {
            }

            this.incident = res.data.incident;
+            this.maintenanceList = res.data.maintenanceList;
            this.$root.publicGroupList = res.data.publicGroupList;
        }).catch( function (error) {
            if (error.response.status === 404) {
@ -946,6 +977,24 @@ footer {
    }
 }

+.maintenance-bg-info {
+    color: $maintenance;
+}
+
+.maintenance-icon {
+    font-size: 35px;
+    vertical-align: middle;
+}
+
+.dark .shadow-box {
+    background-color: #0d1117;
+}
+
+.status-maintenance {
+    color: $maintenance;
+    margin-right: 5px;
+}
+
 .mobile {
    h1 {
        font-size: 22px;
@ -1007,4 +1056,10 @@ footer {
    }
 }

+.bg-maintenance {
+    .alert-heading {
+        font-weight: bold;
+    }
+}
+
 </style>
--- a/src/router.js
+++ b/src/router.js
@ -6,6 +6,7 @@ import Dashboard from "./pages/Dashboard.vue";
 import DashboardHome from "./pages/DashboardHome.vue";
 import Details from "./pages/Details.vue";
 import EditMonitor from "./pages/EditMonitor.vue";
+import EditMaintenance from "./pages/EditMaintenance.vue";
 import List from "./pages/List.vue";
 const Settings = () => import("./pages/Settings.vue");
 import Setup from "./pages/Setup.vue";
@ -14,6 +15,9 @@ import Entry from "./pages/Entry.vue";
 import ManageStatusPage from "./pages/ManageStatusPage.vue";
 import AddStatusPage from "./pages/AddStatusPage.vue";
 import NotFound from "./pages/NotFound.vue";
+import DockerHosts from "./components/settings/Docker.vue";
+import MaintenanceDetails from "./pages/MaintenanceDetails.vue";
+import ManageMaintenance from "./pages/ManageMaintenance.vue";

 // Settings - Sub Pages
 import Appearance from "./components/settings/Appearance.vue";
@ -25,7 +29,6 @@ const Security = () => import("./components/settings/Security.vue");
 import Proxies from "./components/settings/Proxies.vue";
 import Backup from "./components/settings/Backup.vue";
 import About from "./components/settings/About.vue";
-import DockerHosts from "./components/settings/Docker.vue";

 const routes = [
    {
@ -126,6 +129,22 @@ const routes = [
                        path: "/add-status-page",
                        component: AddStatusPage,
                    },
+                    {
+                        path: "/maintenance",
+                        component: ManageMaintenance,
+                    },
+                    {
+                        path: "/maintenance/:id",
+                        component: MaintenanceDetails,
+                    },
+                    {
+                        path: "/add-maintenance",
+                        component: EditMaintenance,
+                    },
+                    {
+                        path: "/maintenance/edit/:id",
+                        component: EditMaintenance,
+                    },
                ],
            },
        ],
--- a/src/util-frontend.js
+++ b/src/util-frontend.js
@ -1,12 +1,7 @@
 import dayjs from "dayjs";
-import timezone from "dayjs/plugin/timezone";
-import utc from "dayjs/plugin/utc";
 import timezones from "timezones-list";
 import { localeDirection, currentLocale } from "./i18n";

-dayjs.extend(utc);
-dayjs.extend(timezone);
-
 /**
 * Returns the offset from UTC in hours for the current locale.
 * @returns {number} The offset from UTC in hours.
--- a/src/util.js
+++ b/src/util.js
@ -7,17 +7,21 @@
 // Backend uses the compiled file util.js
 // Frontend uses util.ts
 Object.defineProperty(exports, "__esModule", { value: true });
-exports.getMonitorRelativeURL = exports.genSecret = exports.getCryptoRandomInt = exports.getRandomInt = exports.getRandomArbitrary = exports.TimeLogger = exports.polyfill = exports.log = exports.debug = exports.ucfirst = exports.sleep = exports.flipStatus = exports.STATUS_PAGE_PARTIAL_DOWN = exports.STATUS_PAGE_ALL_UP = exports.STATUS_PAGE_ALL_DOWN = exports.PENDING = exports.UP = exports.DOWN = exports.appName = exports.isDev = void 0;
-const _dayjs = require("dayjs");
-const dayjs = _dayjs;
+exports.localToUTC = exports.utcToLocal = exports.utcToISODateTime = exports.isoToUTCDateTime = exports.parseTimeFromTimeObject = exports.parseTimeObject = exports.getMaintenanceRelativeURL = exports.getMonitorRelativeURL = exports.genSecret = exports.getCryptoRandomInt = exports.getRandomInt = exports.getRandomArbitrary = exports.TimeLogger = exports.polyfill = exports.log = exports.debug = exports.ucfirst = exports.sleep = exports.flipStatus = exports.SQL_DATETIME_FORMAT_WITHOUT_SECOND = exports.SQL_DATETIME_FORMAT = exports.SQL_DATE_FORMAT = exports.STATUS_PAGE_MAINTENANCE = exports.STATUS_PAGE_PARTIAL_DOWN = exports.STATUS_PAGE_ALL_UP = exports.STATUS_PAGE_ALL_DOWN = exports.MAINTENANCE = exports.PENDING = exports.UP = exports.DOWN = exports.appName = exports.isDev = void 0;
+const dayjs = require("dayjs");
 exports.isDev = process.env.NODE_ENV === "development";
 exports.appName = "Uptime Kuma";
 exports.DOWN = 0;
 exports.UP = 1;
 exports.PENDING = 2;
+exports.MAINTENANCE = 3;
 exports.STATUS_PAGE_ALL_DOWN = 0;
 exports.STATUS_PAGE_ALL_UP = 1;
 exports.STATUS_PAGE_PARTIAL_DOWN = 2;
+exports.STATUS_PAGE_MAINTENANCE = 3;
+exports.SQL_DATE_FORMAT = "YYYY-MM-DD";
+exports.SQL_DATETIME_FORMAT = "YYYY-MM-DD HH:mm:ss";
+exports.SQL_DATETIME_FORMAT_WITHOUT_SECOND = "YYYY-MM-DD HH:mm";
 /** Flip the status of s */
 function flipStatus(s) {
    if (s === exports.UP) {
@ -100,7 +104,7 @@ class Logger {
        }
        module = module.toUpperCase();
        level = level.toUpperCase();
-        const now = new Date().toISOString();
+        const now = dayjs.tz(new Date()).format();
        const formattedMessage = (typeof msg === "string") ? `${now} [${module}] ${level}: ${msg}` : msg;
        if (level === "INFO") {
            console.info(formattedMessage);
@ -303,3 +307,71 @@ function getMonitorRelativeURL(id) {
    return "/dashboard/" + id;
 }
 exports.getMonitorRelativeURL = getMonitorRelativeURL;
+function getMaintenanceRelativeURL(id) {
+    return "/maintenance/" + id;
+}
+exports.getMaintenanceRelativeURL = getMaintenanceRelativeURL;
+/**
+ * Parse to Time Object that used in VueDatePicker
+ * @param {string} time E.g. 12:00
+ * @returns object
+ */
+function parseTimeObject(time) {
+    if (!time) {
+        return {
+            hours: 0,
+            minutes: 0,
+        };
+    }
+    let array = time.split(":");
+    if (array.length < 2) {
+        throw new Error("parseVueDatePickerTimeFormat: Invalid Time");
+    }
+    let obj = {
+        hours: parseInt(array[0]),
+        minutes: parseInt(array[1]),
+        seconds: 0,
+    };
+    if (array.length >= 3) {
+        obj.seconds = parseInt(array[2]);
+    }
+    return obj;
+}
+exports.parseTimeObject = parseTimeObject;
+/**
+ * @returns string e.g. 12:00
+ */
+function parseTimeFromTimeObject(obj) {
+    if (!obj) {
+        return obj;
+    }
+    let result = "";
+    result += obj.hours.toString().padStart(2, "0") + ":" + obj.minutes.toString().padStart(2, "0");
+    if (obj.seconds) {
+        result += ":" + obj.seconds.toString().padStart(2, "0");
+    }
+    return result;
+}
+exports.parseTimeFromTimeObject = parseTimeFromTimeObject;
+function isoToUTCDateTime(input) {
+    return dayjs(input).utc().format(exports.SQL_DATETIME_FORMAT);
+}
+exports.isoToUTCDateTime = isoToUTCDateTime;
+/**
+ * @param input
+ */
+function utcToISODateTime(input) {
+    return dayjs.utc(input).toISOString();
+}
+exports.utcToISODateTime = utcToISODateTime;
+/**
+ * For SQL_DATETIME_FORMAT
+ */
+function utcToLocal(input, format = exports.SQL_DATETIME_FORMAT) {
+    return dayjs.utc(input).local().format(format);
+}
+exports.utcToLocal = utcToLocal;
+function localToUTC(input, format = exports.SQL_DATETIME_FORMAT) {
+    return dayjs(input).utc().format(format);
+}
+exports.localToUTC = localToUTC;
--- a/src/util.ts
+++ b/src/util.ts
@ -6,18 +6,25 @@
 // Backend uses the compiled file util.js
 // Frontend uses util.ts

-import * as _dayjs from "dayjs";
-const dayjs = _dayjs;
+import * as dayjs  from "dayjs";
+import * as timezone from "dayjs/plugin/timezone";
+import * as utc from "dayjs/plugin/utc";

 export const isDev = process.env.NODE_ENV === "development";
 export const appName = "Uptime Kuma";
 export const DOWN = 0;
 export const UP = 1;
 export const PENDING = 2;
+export const MAINTENANCE = 3;

 export const STATUS_PAGE_ALL_DOWN = 0;
 export const STATUS_PAGE_ALL_UP = 1;
 export const STATUS_PAGE_PARTIAL_DOWN = 2;
+export const STATUS_PAGE_MAINTENANCE = 3;
+
+export const SQL_DATE_FORMAT = "YYYY-MM-DD";
+export const SQL_DATETIME_FORMAT = "YYYY-MM-DD HH:mm:ss";
+export const SQL_DATETIME_FORMAT_WITHOUT_SECOND = "YYYY-MM-DD HH:mm";

 /** Flip the status of s */
 export function flipStatus(s: number) {
@ -112,7 +119,7 @@ class Logger {
        module = module.toUpperCase();
        level = level.toUpperCase();

-        const now = new Date().toISOString();
+        const now = dayjs.tz(new Date()).format();
        const formattedMessage = (typeof msg === "string") ? `${now} [${module}] ${level}: ${msg}` : msg;

        if (level === "INFO") {
@ -336,3 +343,79 @@ export function genSecret(length = 64) {
 export function getMonitorRelativeURL(id: string) {
    return "/dashboard/" + id;
 }
+
+export function getMaintenanceRelativeURL(id: string) {
+    return "/maintenance/" + id;
+}
+
+/**
+ * Parse to Time Object that used in VueDatePicker
+ * @param {string} time E.g. 12:00
+ * @returns object
+ */
+export function parseTimeObject(time: string) {
+    if (!time) {
+        return {
+            hours: 0,
+            minutes: 0,
+        };
+    }
+
+    let array = time.split(":");
+
+    if (array.length < 2) {
+        throw new Error("parseVueDatePickerTimeFormat: Invalid Time");
+    }
+
+    let obj =  {
+        hours: parseInt(array[0]),
+        minutes: parseInt(array[1]),
+        seconds: 0,
+    }
+    if (array.length >= 3) {
+        obj.seconds = parseInt(array[2]);
+    }
+    return obj;
+}
+
+/**
+ * @returns string e.g. 12:00
+ */
+export function parseTimeFromTimeObject(obj : any) {
+    if (!obj) {
+        return obj;
+    }
+
+    let result = "";
+
+    result += obj.hours.toString().padStart(2, "0") + ":" + obj.minutes.toString().padStart(2, "0")
+
+    if (obj.seconds) {
+        result += ":" +  obj.seconds.toString().padStart(2, "0")
+    }
+
+    return result;
+}
+
+
+export function isoToUTCDateTime(input : string) {
+    return dayjs(input).utc().format(SQL_DATETIME_FORMAT);
+}
+
+/**
+ * @param input
+ */
+export function utcToISODateTime(input : string) {
+    return dayjs.utc(input).toISOString();
+}
+
+/**
+ * For SQL_DATETIME_FORMAT
+ */
+export function utcToLocal(input : string, format = SQL_DATETIME_FORMAT) {
+    return dayjs.utc(input).local().format(format);
+}
+
+export function localToUTC(input : string, format = SQL_DATETIME_FORMAT) {
+    return dayjs(input).utc().format(format);
+}
--- a/test/backend.spec.js
+++ b/test/backend.spec.js
@ -6,6 +6,9 @@ const { UptimeKumaServer } = require("../server/uptime-kuma-server");
 const Database = require("../server/database");
 const {Settings} = require("../server/settings");
 const fs = require("fs");
+const dayjs = require("dayjs");
+dayjs.extend(require("dayjs/plugin/utc"));
+dayjs.extend(require("dayjs/plugin/timezone"));

 jest.mock("axios");