To my understanding, it shouldn't require that much effort since browsers should already be keeping track of timezone changes, see Chromium's time_zone_monitor

To my understanding, it shouldn't require that much effort since browsers should already be keeping track of timezone changes, see Chromium's time_zone_monitor [0]. Browsers could emit a "timezonechange" event on the window. A quick search of gecko-dev shows entries for both WM_TIMECHANGE and NSSystemTimeZoneDidChangeNotification, although they haven't separated it into its own service. I imagine they also track timezone changes for other platforms. [0] https://source.chromium.org/chromium/chromium/src/+/main:services/device/time_zone_monitor/ https://source.chromium.org/chromium/chromium/src/+/main:ser...