Convert dates between Gregorian and Mayan calendars
The Mayan calendar is cyclic. Each cycle consists of 13 Baktuns (approximately 5,125 years).
The Mayan Long Count calendar consists of cycles: Baktun (144,000 days), Katun (7,200 days), Tun (360 days), Uinal (20 days), and Kin (1 day).