Nyarl's (Nyarlathotep) birthday is on the February 29, but since it is a leap year there is no February 29! February 28 or March 1 is fine too!
Nyarls sleeping in the backstage on a pile of confetti after raving all night. It gets very hot and sweaty in the underground studio so he took off all his clothes. And now there's only one thing left that would make his birthday perfect.