I studied this a few years ago, but I can’t remember the exact numbers. The Mayan calendar rolls over to a new major number about every 600 or so years. I’ve seen some articles that say the calendar works much like a geared series of wheels with numbers on them, something like an odometer. So every few hundred years it rolls over to something like 11000000, 12000000, and the next rollover will be (I think) 13000000.

This is like our calendars rolling over from December 31, 1999 to Jan. 1, 2000.