I try to have that month's KOTH dates out at the first of the month.
Generally speaking they are usually the 2nd and 3rd weekends of the moth but a butterfly doing donuts in Kansas can effect that.
I always send out notices and 2 or 3 day reminders on the KOTH mailing list.
If you want to be added to the KOTH mailing list, send a request to AHKoth-subscribe @ Topica.com .