@rqm

when my laptop's cmos battery was shot I used rdate(1) to fix the time.

https://man.openbsd.org/rdate

@rqm 1. figure out a source to determine your present location; ip, geoip, etc...

2. Run a script via cron that regularly checks that location information.

3. Adjust timezone the normal way, via script.

...

Alternate option:

Run your system as UTC, and maybe GNOME or KDE will allow user localization, or, what I do is the script I use to update my statusbar clock uses a local timezone I set manually.

edit: Also as a user, you can drop 'export TZ=foo' in your shell init.