Maya calendar#Calendar Round
The Calendar Round is an element of the Mesoamerican calendar, particularly known in the Aztec calendar and Mayan calendar. It is caused by a combination of the 260 -day ritual calendar ( Tzolkin Mayan Aztec and tonalpohualli ) with the 365 -day common year ( Xihuitl the Aztecs and the Maya Haab ).
Since the least common multiple of the periodicities of the Xihuitl or Haab ( 365 = 5 × 73 days ) and the tonalpohualli or Tzolkin (260 = 4 × 5 × 13 days) 4 × 5 × 13 × 73 days, the combination of the two repeat identical cycles after this time ( 18,980 days ). This period is called the calendar round ( Aztec: xiuhmolpilli, annual bond). Within this period, one consisting of the two shorter cycles dates eg from 6 Edznab 11 Yax in the Mayan calendar is clear. A corresponding day name among the Aztecs is not known.
Fixed daily were used to name the years for the common years ( Xihuitl, Haab ). This year name composed of the numbers 1 to 13 and 4 of the 20 signs of the tonalpohualli or Tzolkin (these were referred to as annual support, but were in the various calendars not identical. The order of these years the name was repeated identical within the calendar round again and was for identification the years used throughout Mesoamerica. A count of the calendar rounds but there was not.
The Maya and adjacent former cultures ( Olmec ) used the Long Count, which made it possible to provide historical data clearly for longer periods.