It has to do with broadcasting tape delays for different time zones. Many “live” shows air at the same clock time in each time zone, with the exception of the Central time zone. If it airs at 8pm in the Eastern zone, it can be delayed two hours for Mountain time, and three hours for Pacific time. However, because a one-hour delay used to be nearly impossible for station operators to do in the Central time zone (lazy bastards), they would allow the show to air an hour earlier on the clock. So 8/7 Central means it will air at 8:00 in each time zone except Central, where it will air at 7:00.
However, I think the overshare is simply Rena’s stupidity.