Here's my idea, still needs work, just throwing it out there
-say a semester ic lasts two or three months time irl. so a person has 3 months of real world time to complete his/her subjects in their respective threads. (this is a very strict timeline, but here's how I propose to make it fluid.) taking into account that not everyone starts at the same time in taking classes, I say the three months time will not be set as a standard on everyone.
ie. jan - mar, april - july...
but instead have them bind themselves three months from when they start taking classes.
ie. I joined in june, and A joined in july. So while A has until september to finish his classes, I only have till august to finish mine.
This needs major work and has flaws. but you guys wanted suggestions. :D