Set timezone publish at the device level to prevent all devices writing to the timezone field.

Author: Half-Shot

src/components/views/settings/tabs/user/PreferencesUserSettingsTab.tsx

@@ -143,7 +143,7 @@ export default class PreferencesUserSettingsTab extends React.Component<IProps,
         "MessageComposerInput.insertTrailingColon",
     ];
 
-    private static TIME_SETTINGS = ["showTwelveHourTimestamps", "alwaysShowTimestamps", "userTimezonePublish"];
+    private static TIME_SETTINGS = ["showTwelveHourTimestamps", "alwaysShowTimestamps"];
 
     private static CODE_BLOCKS_SETTINGS = [
         "enableSyntaxHighlightLanguageDetection",
@@ -310,6 +310,7 @@ export default class PreferencesUserSettingsTab extends React.Component<IProps,
                         </div>
 
                         {this.renderGroup(PreferencesUserSettingsTab.TIME_SETTINGS)}
+                        <SettingsFlag name="userTimezonePublish" level={SettingLevel.DEVICE} />
                     </SettingsSubsection>
 
                     <SettingsSubsection

src/settings/Settings.tsx

@@ -656,7 +656,8 @@ export const SETTINGS: { [setting: string]: ISetting } = {
         default: "",
     },
     "userTimezonePublish": {
-        supportedLevels: LEVELS_ACCOUNT_SETTINGS,
+        // This is per-device so you can avoid having devices overwrite each other.
+        supportedLevels: LEVELS_DEVICE_ONLY_SETTINGS,
         displayName: _td("settings|preferences|publish_timezone"),
         default: false,
         controller: new ServerSupportUnstableFeatureController(