PERPETUAL CHRONOLOGICAL CALENDAR. 



-t-^-V qfe n H*r- 



This calendar enables us to determine the position in the grand era of any date where 

 the number of the ahau and katun, or of the katun only, is given. Take, for instance, 

 the important date 9 — 15 — 20 — 18x20 — 4 Ahau-13 Yax. We know here that it is 

 in a ninth cycle, but will assume that we do not. There are no days, chuens, or ahaus 

 in this date — the extreme numeral or each of these periods indicating it to be the 

 beginning of an initial one — so we turn at once to the table of katuns to find where 

 4 Ahau-13 Yax occurs. We discover it to be the beginning of the first katun in 

 the first column. But, as we know it to be the fifteenth katun of a cycle, we 

 must count backward fifteen katuns. This we do, beginning at the bottom of the 

 thirteenth column. Counting upward fifteen we come to 8 Ahau-13 Ceh, the 

 beginning of the cycle. Going with this date to the cycle table we find it in the 

 tenth column, and discover that it occurs in the 9th cycle of the great cycle 

 beginning with 4 Ahau-8 Cumhu (every figure of 4 in the cycle table is the beginning 

 of a great cycle). With 4 Ahau-8 Cumhu we go to the great cycle table and find 

 that the great cycle beginning with that date is the 54th. Thus we have ascertained 

 the full date to be 54—9—15—20—18x20—4 Ahau-13 Yax. 



Or take the initial date of the Temple of the Sun at Palenque. It is 1 — 18 — 5 — 3 

 X6 — 13 Cimi-19 Ceh. Here we have ahaus, chuens, and days. We first refer to the 

 Annual Calendar to find 13 Cimi-19 Ceh, and, going back 3 chuens and 6 days — 

 or 66 days — come to 12 Ahau-13 Chen, the beginning of the fifth ahau. We then 

 turn to the ahau table of the Perpetual Calendar for that date, and, counting back 

 five ahaus, arrive at 6 Ahau-18 Yax, the beginning of the katun. With that date 

 we go to the katun table, and, counting back eighteen katuns from it, come to 

 3 Ahau-13 Chen, the beginning of the cycle. Taking that date to the cycle table we 

 find it belongs to the first cycle of the grand cycle beginning with 4 Ahau-8 Cumhu. 

 We know where we are now, from the preceding trial. The date is in the same 

 great cycle as the other, but they are more than three thousand years apart. 



