There was no email involved. That was why I forgot it. It relies on keeping an eye on Facebook, which, generally, I don't.

The silly thing was that I've been to the last several Rosh Chodesh events; I should have realised there'd be one this week too. (Though I suppose it could also have been today, as it's a two-day Rosh Chodesh (and the moon isn't actually new until 3:44 on Thursday morning).)