It seems to be only these two festivals, specifically, because they're the only ones appearing back to back in the same square.
Basically there are three ways of dealing with this:
1. Hardcore: Never visit GeekCon
2. Live in the neighbourhood. Then the problem never happens, since you are "staying the duration of the festival" just by being on your lot.
3. Make sure you stay at GeekCon until it has completely "uninstalled" itself before going home. First time I did this I had to have a Sim napping on a parch bench the whole night. Basically make sure at least one Sim in your family has enough Energy to last past midnight without collapsing or missing work the day after.