Firefox not updating timezone on change in system timezone

Question

I want to use browser time zone to present date times according to user's timezone. On browser start up Firefox gives accurate timezone, but if browser is open and I make change in system timezone then if I check time zone in my browser it will give the timezone on which browser was launched. It doesn't update timezone runtime. This issue only persist in Firefox, chrome is working fine.

Is there any way to get the updated system timezone without closing Firefox browser? I am using this command to fetch current timezone offset -(new Date().getTimezoneOffset() / 60)

Answer 1

This is a (5 year old) bug in Firefox which has been reported but hasn't been fixed yet.

see https://bugzilla.mozilla.org/show_bug.cgi?id=1348916

and

https://bugzilla.mozilla.org/show_bug.cgi?id=1567862

(1567862 was closed as dup, but the reporter of the bug was in the exact situation that a commenter to OPs post said doesn't happen often).

I was bitten by this very bug today as well.

And unlike one of the bug reports, it seems to persist across a page reload/refresh. Browser or tab needs to be closed and reopened. Chrome and Edge do not have this issue.

Regardless of whether people travel across timezones with browser open or not, it's a bug and so it should be fixed. But it is low priority on Mozilla's list, so don't hold your breath waiting.