Not all time zones observe ”daylight saving” or ”summer” time
Calling your timezone by it's ”local” name (eg Eastern) handles whatever the current local time is without having to remember when to add (or subtract) extra time from UTC
August 30, 2020 at 01:42PM
via reddit https://www.reddit.com/r/explainlikeimfive/comments/ijgmvi/eli5_is_there_a_specific_use_for_stating_pdt_pst/g3dkiyb?utm_source=ifttt