I think this might be ambiguous, since "Pacific/$city" refers to a part of the world that the west of the US ("PT") is not part of.

I've decided to add "Pacific Time" to my "dateparse"[1] script, though.

    $ TZ=America/Chicago dateparse '6:30 PM Pacific time'
    6:30 PM Pacific time: assuming PDT
    1647480600  Wed Mar 16 20:30:00 CDT 2022

[1] https://github.com/pflanze/chj-bin/blob/master/dateparse