[OFF TOPIC] Like 404 (4th April), what others date you know relate programming?

Question

Like we know today 4th of April, we are all enjoying 'Day not found' day, what are the other days you know which can be call same as today.
I know one - Pi day which just went on 14th of March (314).
P.S. Don't try answer with 405, 406 codes we all know that.

Answer 1

May the 4th = star wars day ^^
https://www.sololearn.com/learn/7963/?ref=app

Answer 2

//Some are
//pi Day
https://www.sololearn.com/learn/17160/?ref=app
//web day
https://www.sololearn.com/learn/17125/?ref=app

Answer 3

women day