The American anthropologist Suzanna W. Miles who did field work among the Quiché-Maya in the forties, describes the virtue of the day lords in the following way:

"Through individual consultation of the shamans (i.e. the aj k'ij ), the auspices and authority of the lords of the days and numbers direct economic enterprise, designate the days of agricultural labor, and control life-crises. According to the favor of the days, land is purchased, sales made in the market and profit accrued. The day lords designate the times for planting and harvest. The lords of the days can maintain health and foretell illness or death; betrothal and marriage are guided by the disposition of the days; and obligations to the dead are fulfilled on days affiliated with the souls of the ancestors. Each town has one or more day lords with special powers, and it is known that such a lord, with his number, will determine the character or occupation of the child born within his day".

Suzanna Miles also observed that in areas of highland Guatemala where the thirteen numbers of the tsolk'in had been lost, the twenty named days survived as a cycle and assumed the divinatory functions of the tsolk'in as a whole. Thus, this element, the twenty days of the tsolk'in, is the lowest surviving form of the Maya calendar count, and represents the core, the ultimate reduction of the calendrical structure.

Such is also the case with the prognostication tables, which have come down to us in the literary tradition of the Maya of Yucatan. In the Books of Chilam Balam of the 18th century we find four lists of days, each day with its specific properties and prognostications annotated. These prognostication tables are written in Mayat'an, the Maya idiom of Yucatán, by means of a specially adapted Latin alphabet, but as a comparison with passages of similar content in the Codex Dresdensis shows, they no doubt have their origin in the hieroglyphic books from pre-Columbian times.

The most precise, and also the most extensive divinatory list in the Books of Chilam Balam is List # I from the Book of the Chilam Balam of K'awa, a small village not far from Chichén Itzá, the famous ancient Maya capital of Northern Yucatán. It consists of the names of the twenty days of the tsolk'in and the specific properties, which these days have, in shaping the destinies, the qualities, and the basic behavior, and the future occupations of men and women who were born under their powers.

In his Relación de las cosas de Yucatán (Report on the things of Yucatán) of 1566, Fray Diego de Landa briefly refers to this ritual of calendrical prognostication on the fate of the newly born among the Maya of 16th century Yucatán:

Once the babies are born they bathe them immediately, and once they were through with the painful process of flattening their foreheads and heads, they went with them to the priest so that he might foresee their destiny and foretell the profession they were going to have. (Landa, Tozzer-edition, page 129)

This information of Landa's in conjunction with the pattern of Maya calendrical prognostication described by Leonhard Schultze Jena and Suzanna Miles for the present day Quiché-Maya complement each other, giving us some basic idea of what the 260-day-calendar was about. Recently two scholars have gone farther, in order to conceive a clearer idea of how calendrical divination actually works in the minds of the present day Maya and what effects it has on their society.