how is it that the mayan calendar corrresponds with our? did the spanish tell them about the birth of christ?

Question

and why is it that the mayan calendar supposedly only goes to the year 2012?

Answer 1

It corresponds with ours because archaeologists, anthropologists etc have painstakingly correlated it using known dates in both calendars (such as the day Cortez arrived at Tenochtitlan).
The Maya had no concept of Jesus or our year numbering system.
And the Mayan Long Count calendar does NOT end in 2012. The 13 Baktun begins on 12-21-2012 (A baktun is 396 years long)--it's like our calendar going from 1999 to 2000, same artificial hysteria.