1929 :-) https://www.gnu.org/fun/jokes/ed-msg.html

1980-01-01 00:00:00 is probably more recognisable for those in the DOS era.

Ha! Mine are four hours older than yours!

the oldest i have seen on one of my machines at some point was on broken file systems where the date got mangled. some even much older than 1970.

i just found a few hundred rust files coming out of cargo crates dated 1970.1.1 and 1973.11.30. i had no idea that rust was so old. but it explains the name at least ;-)