You could simply set the TZ variable to a fixed offset: $ TZ='<UTC-7>+7' date -R...

You could simply set the TZ variable to a fixed offset:

    $ TZ='<UTC-7>+7' date -R
    Sat, 16 Jul 2016 11:04:52 -0700

Or use Sonora in Mexico:

    $ TZ=:America/Hermosillo date -R
    Sat, 16 Jul 2016 11:05:39 -0700

Another option is Pitcairn Island, which is -0800 all year.

    $ TZ=:Pacific/Pitcairn date -R
    Sat, 16 Jul 2016 10:06:23 -0800

though the standard abbreviation, PST, is probably confusing.