The Mayan/Aztec calendar can calculate any date going backwards or forwards for millions/billions/infinity years, days. Their calendars are based on the sun, AND the moon, AND the Milky Way Galaxy rotation.
Each of these calendars works like cogs in a giant wheel.
Mayans start their "new calendars" after every 5,000+ years.
As far as I and people that keep track of these "dates" know, the Mayan calendar is the most extensive and accurate calendar ever invented.
The cogs are:
1. The Haab - very close to our 365 day year
2. The Tzolkin - very close to a lunar style calendar
3. The Long Count Calendar - Each such cycle is calculated to be 2,880,000 days (about 7885 solar years)
So, just by turning the big wheel of time (with the 3 cogs in it), they can calculate any date in the universe.
BTW. - Calendars are man made measurements. Just like a ruler is made for measuring distance, calendars are made for measuring time.
Calendars measure time RELATIVE to our system of measurement and reference points. Time itself is infinite.