shtool-mdate(1) on Linux
The text 2b522a057dae, as Debian 10 (Buster), Debian 9 (Stretch) shipped it.
GNU shtool pretty-print last modification time
Flags it lists
-
--digits -
--field-sep -
--newline -
--order -
--shorten -
--zero -
-d -
-f -
-n -
-o -
-s -
-z