The Conventional Year.

It has been stated that the Mayas arrived at a conventional 365 day year made up of eighteen months of twenty days each plus a short period of five days that fell after the eighteen regular months had been counted. The Mayan month names are as follows:—

1. Pop 2. Uo 3. Zip 4. Zotz 5. Tzec 6. Xul 7. Yaxkin 8. Mol 9. Chen 10. Yax 11. Zac 12. Ceh 13. Mac 14. Kankin 15. Muan 16. Pax 17. Kayab 18. Cumhu 19. Uayeb (five additional days)

Fig. 41. The Nineteen Month Signs of the Mayan Year. The first example in each case is taken from the inscriptions and the second from the codices. The last details are signs for zero.

Since there are twenty days or positions in the month and likewise twenty distinct day names in the tzolkin, falling in regular order, it follows that each day would always occupy the same month position were it not for the offset at the end of each year caused by the short Uayeb period. As it is, any day name occupies the same month position during the course of an entire year and a position five days in advance during the course of the following year. Since five is contained four times in twenty there can be only four shifts, the fifth year showing the same arrangement as the first. The following table gives the month positions of each day name during the changes of four consecutive years as these are recorded in the ancient inscriptions.

[Plate XXII.]

Scheme of the Mayan Calendar as presented in the Codex Tro-Cortesianus. In the center is Itzamna, the God of the Sky, and his spouse, under what has been called the celestial tree. The band of hieroglyphs that frames in this picture contains the twenty day signs of the Mayan month. The figures on the outside are arranged in four groups, according to the four directions of the compass. At the top or east we again see Itzamna and his mate. In the north, or right hand quarter, human sacrifice is shown and the Death God sits opposite the God of War. In the east and in the south are also shown pairs of divinities. A series of dots running from one day sign to another covers the tzolkin or 260 day cycle of names and numbers.

Ik Manik Eb Caban 0 5 10 15
Akbal Lamat Ben Eznab 1 6 11 16
Kan Muluc Ix Cauac 2 7 12 17
Chicchan Oc Men Ahau 3 8 13 18
Imix Cimi Chuen Cib 4 9 14 19