31/12 

31/12 is the English way of writing December 31st in shorthand.

England:

Someone is told to write the date on December thirty-first but doesn't have very much time so they write 31/12.

31/12 by Walking Talking Dictionary October 28, 2006

31.12 

People Born on 31.12 have a high IQ and a hugh cocks.

Im Born on 31.12 so im schmart

31.12 by Stece_wood6 October 28, 2020

31.12 

People Born on this date have a very high IQ and Also have big wieners

"Wow your Winter is very big, were you Born on 31.12?"
~smart~

31.12 by Stece_wood6 October 28, 2020

31-12-9999 

The end of all existence.

Me: OMG OMG OHH NOOOOOOOOOOOOOOOOOOOOO
My Bro: what?
Me: it's 31-12-9999
My Bro: OH SHID

31-12-9999 by ƪĄİŁÞĞĐĶŪŒƏəŢĶÑØĽĢŘßĶŐŁŚ§ÇĶ£€ June 2, 2022

12.31.23

The last day of 2023 in American date notation
Kinda similar to 12.12.12 or 02.22.22

12.31.23 is the perfect date

12.31.23 by Kajmarez July 11, 2023

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 

You type this when you have way too much free time or are way too bored.

Teacher: lets count to 50!
Students: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50!

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 by KeindlyGamer123 October 8, 2019

3 1/2 inch floppy 

a disk for getting stuff from 1 pc to another 1.
but mostly used in jokes.

(when a computer rejects a 3 1/2 inch floppy)
lorlor: aww thats mean i wouldnt reject a 3 1/2 inch floppy.
georgie: girl, your standards are LOW!

3 1/2 inch floppy by memememememememememememe May 4, 2006