Yucatan Before and After the Conquest, by Diego de Landa, tr. William Gates, , at sacred-texts.com
Together with the characters of the Indians shown above in our chapter 100 (Sec. xxxiv), they gave names to the days of their months, and from all the months together they made up a kind of calendar, by which they regulated their festivals, their counting and contracts as business, as we do ours; save that the first day of their calendar was not the first day of their year, but came much later; this being the result of the difficulty with which they counted the days of the months all together, as will be seen in the Calendar itself we shall give herein later. The reason is that although the signs and names of the days of their months are twenty, they were used to count them from 1 to 13; after the 13 they return to 1 again, thus dividing the days of the year into twenty-seven thirteens or triadecads, plus nine days, without the supplementary ones.
With these periodical returns and the complicated count, it is a marvel to see the freedom with which they know how to count and understand things. It is notable that the dominical always falls on the first day of their year, without fail or error, no other of the twenty ever taking that position. They also used this way of counting to bring out by the aid of these characters a certain other count they had for their ages; also other matters which, although they were important for them, do not concern us much here. We shall therefore be content with saying that the character or letter with which they began their count of the days or Calendar is called Hun Imix (One Imix), which is this: and which has no fixed day on which it must fall. For each modifies its own count, and with all this the dominical letter as they have it never fails to fall on the first day of the following year.
Among these people the first day of the year always fell upon our 16th of July, and was the first of their month Popp. Nor is it to be wondered at that this people, however simple as we have found them in many ways, also had ability in these matters and ideas such as other nations; for in the gloss on Ezekiel we find that according to the Romans January began the year, according to the Hebrews April, according to the Greeks March, and according to the Orientals October. But, although they began their year in July, I put their calendar here in the order of ours, and parallel, so that our letters and theirs will come noted, our months and theirs, together with their above-mentioned count of the thirteens, placed in the order of their progression. *
And since there is no need for putting the calendar in one place and the festivals in another, I shall place in each of the months its festivals and the observances and ceremonies with which they celebrated it. Thus I shall do as I before promised, giving their calendar and with it telling of their fasts and ceremonies wherewith they made their idols of wood, and other things; all of these things and what else I have told of these people serving no other purpose than to praise the divine goodness which so has permitted an] has seen well to remedy in our times. This in order that, in recording them, with Christian entrails we pray Him for their preservation and progress in true Christianity; and that those whose charge this is may promote and aid this end, so that neither to this people for their sins, nor to ourselves, may there be lacking help; nor may they fail in what has been begun and so return to their misery and vomitings of errors, thus falling into worse case than before, returning the evil ones we have been able to drive out of their souls, out of which with so laborious care we have been able to drive them, cleansing them and sweeping out their vices and evil customs of the past. And this is not a vain hope, when we see the perdition which after so many years is to he seen in great and very Christian Asia, in the good, Catholic and very august Africa, and the miseries and calamities which today our Europe suffers, and where in our nation and houses we might say that the evangelical prophecies over Jerusalem have been fulfilled, where her enemies encircle her and crowd her almost to the earth. All of this God already had permitted for us, as we stand, were it not that his Church cannot pass, neither that which is said concerning her: Nisi Dominus reliquisset semen, sicut Sodoma fuissemus.
68:* In the pages following, the manuscript sets out in full each of the successive 365 days, p. 69 with the names and character together; with each it gives the day of the European month, and also the succession of the Church dominical letters, A b c d e f g. To July 16th, 12 Kan, the 1st of Pop, he assigns the church dominical A, fixing his calendar as computed for the year 1553, when July 16th fell on Sunday, and the only year between 1525 and 1581 when it did so fall. The present abbreviated transcript of Landa's work, made in 1566, was thus written thirteen years after the computation was made.
In the manuscript the series of days begins not with the Maya Pop the 1st, but with our Jan. 1st; then when it reaches July 15th, with 12 Lamat, it skips a day, to begin the year, incorrectly, with 12 Kan. A year beginning with 12 Kan must end with 12 Lamat, with the next year beginning with 13 Muluc. It therefore seems most probable that the later copyist simply transposed the two halves of the Maya year so as to start with our January, and hence the obvious error. For now that our calendar correlation is definitely established, we know that July 16th, Sunday, 1553, was 12 Kan, the 1st of Pop, and the 12 Lamat then came on July 15th, 1554, to he followed regularly by 13 Muluc on the 16th. And this completely disposes of any idea that an extra bissextile day was inserted every four years.
In addition to repeating the glyphs for the days, the manuscript inserts those for the successive uinals or 'months,' as they come. We shall do the same here, using the standard type forms as we have for the day-signs, also showing the forms in the manuscript. We shall also arrange the calendar in Maya form, beginning with the month Pop.