How to: Tell time like the ancient Maya

We would be remiss not to point you toward this nifty, interactive version of the Maya's long count calendar system. It does a great job of helping explain the Mayan number system and how those numbers come together to mark important dates. 

If you're interested in Mayan hieroglyphics, we'd also recommend reading the book A Forest of Kings, which explains how the ancient Maya wrote and what their writing really tells us about their history.