I'm only just now realizing - perhaps the best time would be directly after HERC costume contests?
Plenty of people would likely already be on at that point, and then a potential over-time on "The Memorizer" event - however unlikely - wouldn't interfere with an already well-established event.
That, or I should move the event away from Thursdays and on to a different day - but then the match-up with Nov. 30th would no longer be there.