Fix `Same As Server Timezone` do not save correctly

server/model/maintenance.js

@@ -47,7 +47,8 @@ class Maintenance extends BeanModel {
             cron: this.cron,
             duration: this.duration,
             durationMinutes: parseInt(this.duration / 60),
-            timezone: await this.getTimezone(),
+            timezone: await this.getTimezone(),         // Only valid timezone
+            timezoneOption: this.timezone,               // Mainly for dropdown menu, because there is a option "SAME_AS_SERVER"
             timezoneOffset: await this.getTimezoneOffset(),
             status: await this.getStatus(),
         };
@@ -153,7 +154,7 @@ class Maintenance extends BeanModel {
         bean.description = obj.description;
         bean.strategy = obj.strategy;
         bean.interval_day = obj.intervalDay;
-        bean.timezone = obj.timezone;
+        bean.timezone = obj.timezoneOption;
         bean.active = obj.active;
 
         if (obj.dateRange[0]) {
@@ -316,7 +317,7 @@ class Maintenance extends BeanModel {
     }
 
     async getTimezone() {
-        if (!this.timezone) {
+        if (!this.timezone || this.timezone === "SAME_AS_SERVER") {
             return await UptimeKumaServer.getInstance().getTimezone();
         }
         return this.timezone;

src/pages/EditMaintenance.vue

@@ -203,8 +203,8 @@
                                     <label for="timezone" class="form-label">
                                         {{ $t("Timezone") }}
                                     </label>
-                                    <select id="timezone" v-model="maintenance.timezone" class="form-select">
+                                    <select id="timezone" v-model="maintenance.timezoneOption" class="form-select">
-                                        <option :value="null">{{ $t("sameAsServerTimezone") }}</option>
+                                        <option value="SAME_AS_SERVER">{{ $t("sameAsServerTimezone") }}</option>
                                         <option value="UTC">UTC</option>
                                         <option
                                             v-for="(timezone, index) in timezoneList"
@@ -419,7 +419,7 @@ export default {
                     }],
                     weekdays: [],
                     daysOfMonth: [],
-                    timezone: null,
+                    timezoneOption: null,
                 };
             } else if (this.isEdit) {
                 this.$root.getSocket().emit("getMaintenance", this.$route.params.id, (res) => {