There are a lot of prophesies and predictions out there, some are quite fascinating and give certain celestial events as “signs of the end of days”. The popular religions have their predictions, if you follow them, even a count down via different prophesies. None of them seem to refer to a specific date except your Mayan calendar, as you mentioned. If you do a Google search under “end of days” or “day of judgment” you see all kinds of information under Wikipedia. Maybe that’s some of what your professor was referring to as well.
Personally, I hope not! 4 years is not a long time for us to get our affairs in order.