Mayan_Tzolkin_Calandar

The Tzolkin calendar combines twenty day names with the thirteen numbers of the trecena cycle to produce 260 unique days. It was used to determine the time of religious and ceremonial events and for divination. Each successive day was numbered from 1 up to 13 and then starting again at 1. Separately from this, each day was given a name in sequence from a list of 20 day names.The system started with 1 Imix', which was followed by 2 Ik', 3 Ak'b'al and so on up to 13 B'en. The trecena day numbers then started again at 1 while the named-day sequence continued onwards, and so the next entries in the combined sequence were 1 Ix, 2 Men, 3 K'ib', 4 Kab'an, 5 Etz'nab', 6 Kawak, then 7 Ajaw. With all twenty named days used, these now began to repeat the cycle while the numbered portion continued, so the next day after 7 Ajaw was 8 Imix'. The repetition of these interlocking 13- and 20-day cycles therefore took 260 days to complete (that is, for every possible combination of number/named day to occur once).