Answer by Edward Brey for Unable to change the time zone in Windows 10

Windows 10 Home can get in a state where it requires admin to change the time zone, even though there's no group policy. It worked for me to run tzutil as a standard user with privilege elevated via UAC (as opposed to using the admin account, which the OP tried).

1. Open an admin console (Windows+X,A).

2. Enter tzutil /l to list time zone choices.

3. Copy the the one you want to the clipboard and paste it in quotes after tzutil /s, e.g.:

    tzutil /s "Pacific Standard Time"