Correct me if I'm wrong... But from what I read it's about twenty minutes before the event itself. (e.g. 7:40 - 8 for 8 pm Wishes)
And it may be best to replace all your selections to get Wishes to show up as opposed to changing an existing event. I read that across multiple threads.
I've been checking daily and I was digging on the board and found prior release dates are inconsistent:
Sep 27 - October
Nov 1 - Nov
Nov 27 - Dec
Jan 30 - February
Dec 20 - Jan
Feb 26 - March
Should be any day now!
Hopefully the whole month will be released but I've also read on here that sometimes it's staggered.
Everyone post when you can reserve and which date you were able to get!