Sanctuary spell duration varies?

I have noticed my character who has mastered Sanctuary, that when it casts upon itself there is a three hour spread, meaning the spell's duration is between 6 - 8 hours.

Is this normal? Or should the spell be consistent duration wise?

Thanks*!*

hrm, I don't think mine does... least not that I have noticed. :confused:

There's an algorithm for it, i would think it is something like proficiency + level + variable(to keep it at the right levels) = affected time

Yeah, it varies 7-9 for evils and 10-12 for goods at 50, or something like that. Goods have longer sanctuary anyway. Proficiency has nothing to do with time affected.

Appreciated.