Fanlore says it was chopchica talking about signups in 2007, but I thought I remembered coffeeandink/melymbrosia talking about the deadline falling on a Jewish holiday in a different year. It's something that has come up a couple of times, to be sure.

https://fanlore.org/wiki/Yuletide_Controversies#Religion_and_Yuletide

https://chopchica.livejournal.com/99840.html