From what I understand the FBS can not start before the Thur before the first Sat in September (or something like that).
But yes I would say that many on Thur/Fri is more than usual. The Monday and or Sunday is not unusual - when not competing against NFL on Sun/Mon the college game will take advantage.
I'm curious how much Thur will change for college games with Thur NFL games going to network TV. It could cause a huge drop in ratings for CFB on Thur...