What strftime/date formatting does Grafana use (Timezone issues)

I’m display the date in the display name of a panel from an epoch timestamp on Grafana using ${var_name:date} (actually ${__cell_1:date}).

This gives the data with the correct time zone, 2023-07-28T15:43:22.000Z, 3:43 pm PST is the time that I want.

However, if I go to format the date myself to something easier to read, like ${__cell_1:date:YYYY-MM-DD_HH:mm:ss}, the timezone changes and I get 2023-07-28_08:43:22, 8:43, which I believe is UTC time (7 hour difference). How can I format it the way I want but show it in PST time?