Leaving it as "check translation" because I'm not 100% sure about the 呑めん + めんばー portmanteau. I checked some webpages that talk about this commemorative day, but it seems all of them just use the sentence without explaining it further.
The 10th of November is
Abstinence Announcement Day!
Celebrated in this day due to the pun with "I'm from the 'I can't drink anymore' club" and "To stop drinking"!
The pun:
For the month: "I can't drink anymore" > "Mou sake wa nomenai". Then "nomenai" gets shortened to "nomen". Then this gets (possibly) combined with "member" for "nomember", which is close enough to November.
For the day: "To stop drinking" > "Sake ga tomaru". Tomaru starts with "to" which is one of the ways to say 10 in the hifumi numbering system.Hhey! Ghive me bacck my shakee———!You have been drinking too much!This is stealing out of loveSake
