Meeting schedules differ for different congregations. Midweek you have the CLAM (Christian Life and Ministry) and the Service meeting. On the weekend, probably Sunday you have the public talk and Watchtower Study. I and many here have been out too long to have attended some of the new ways that they do things. They have a new Bible that was released just before we left, they have tv screens in Kingdom Halls where mindless drones watch video propaganda now, and things have changed quite a bit.
As to the midnight cry, I can't remember them ever specifying much on that one point. So I'm no help there.
Honestly, your question was oddly specific as to the midnight cry. I didn't know you had been here so long, have never seen you, and figured you were just an average "worldly" person trying to learn about JWs so I mentioned generalized places that might help you.
So, what's the deal? Are you trying to help someone that you love that's a JW, or are you trying to become a JW for someone you love, or just curious? Maybe we can't help with these specifics so much but some context would help us to help you in some way.