The Mayans also used the Tzolkin calendar

The Mayans also used the Tzolkin calendar, which is 260 days, the same amount of time that a pregnancy lasts. The Mayan Tzolkin calendar has 20 days signs combined with the numbers 1 through 13. It does not equal out to a full calendar year, and as such is not readily available for astrological purposes. The modern Dreamspell calendar system by Jose Arguelles is based on the Tzolkin calendar, however, it is not known what purpose the Tzolkin calendar held for ancient Mayans, and his Dreamspell is a modern rendition which he has created his own meanings for.