I recently had to change the time zone on a linux server, and while linux handles time zones and locales well, changing the system’s time zone isn’t well documented.
I searched for a single command that would do it, probably run as root, but no
tzfile(5) have lots of good information, but none of
them actually changes the time zone.
After some googling, I determined that
/etc/localtime determines the system’s
time zone. It’s usually a copy of or symlink to a file in
ended up symlinking it to
PST8PDT, for Pacific Time. If you’re in another time
zone, the file names should be self-explanatory. (There’s more
information on the
debian-user mailing list.)