A History of Short Words

From the New York Times Crossword Puzzle

PST

Sun, 19 Jun '22
It's observed at LAX during part of the year
Sun, 3 Apr '22
SFO setting: Abbr.
Thu, 13 Jan '22
Winter hrs. in Seattle
Thu, 26 Aug '21
L.A. winter hrs.
Mon, 23 Aug '21
West Coast winter hrs.