A History of Short Words

From the New York Times Crossword Puzzle

GMT

Fri, 20 Jun '25
Clock standard: Abbr.
Wed, 10 Jul '24
Clock-setting standard: Abbr.
Sun, 19 Feb '23
Big Ben hrs.
Wed, 30 Mar '22
Intl. standard used by many astrologers
Tue, 6 Jul '21
Hrs. at the prime meridian