Then simply make sure that Set time zone automatically is turned off, and you can select your proper time zone and let Windows do the rest of the work.

If the Set time zone automatically is greyed out on your Winmdows 11/10 computer, follow the solutions mentioned in this post to resolve the issue.

Next, restart Windows and then return to the same place in Settings and click on turn on Set Time Zone Automatically.

Windows 11/10 includes tzutil.exe, Command Line Windows Time Zone Utility that can be used to change Time Zone or get current Time Zone details.