I'm pretty sure the next activity period is June 24th. Hope this helps you.
I'm actually highly confident that there isn't a "date" when the activity changes, but rather just a 2 week period for each user. I could be wrong about this, however.
EDIT: Never mind. I looked at the links and there is a date. Sorry.
My activity count moves with my post and ranks were given at any time I reach the required Activity, there is something else not properly explain in this activity count, probably post deletion also carry penalty that will reduce your activity valuation and this part is not explain to user
