I was trying to figure out how contests work before I entered one, and I noticed something puzzling, All of the accumulated times for the finishers of previous weekly contests (that I have seen so far) appear to be 2 hours or less, but I cannot find any mentoin of such an overall calendar/clock time-limit in the contest rules.

I have tried to search for this, but all I come up with is questions about the run-time limits for individual questions.