Arguably the most enigmatic of the Maya calendar cycles, the 819-day count has challenged modern scholars for decades. Even today it is not completely explained and there are several areas for further research, including its relationship with the synodic periods of the planets visible to the naked eye. Earlier research has demonstrated a four-part, color-directional scheme for the 819-day count such that each of the calendar stations progress in increments of 819 days in cycles of 4 × 819 days. Although prior research has sought to show planetary connections for the 819-day count, its four-part, color-directional scheme is too short to fit well with the synodic periods of the visible planets. By increasing the calendar length to 20 periods of 819-days a pattern emerges in which the synodic periods of all the visible planets commensurate with station points in the larger 819-day calendar.

This study places the recently excavated ninth-century A.D. four-part calendrical notations at Xultun (Lunar Table, Ring Number, Long Count, and Multiplication Table) in the context of both Classic monumental inscriptions and astronomical knowledge in the Postclassic Dresden Codex. We demonstrate that the Lunar Table employed a formula attributed to Palenque and that it could have been used as a device to determine precisely where to break the sequence of alternating 29- and 30-day months one finds on dated monuments. All four categories found at Xultun appear in the Dresden Codex. The Ring Number, which bridges a date in the deep past with one in the recently completed era, is a perfect fit with one of the most fundamental Dresden eclipse cycles. Our analysis of glyphs accompanying the Long Count date enables us to place candidate eclipses, especially one that corresponds with a conjunction of Mars, in real time. We argue that the large multiples were extracted from, or prepared for, warning tables like the Dresden eclipse table, and we demonstrate why such tables must have existed well before the Xultun inscriptions. Thus, while the writings in the Dresden manuscript constitute a finished product, the writing on the wall of residential Structure 10K-2 is more akin to what one might find in an astronomer's notebook.

The Palace of the Governor at Uxmal is known from previous scholarship to be associated with Venus in terms of both its sculptural decoration and its orientation, which is aligned to an infrequently occurring extreme position of Venus on the horizon. A hieroglyphic inscription above the central doorway of the Palace is shown here to relate specifically to the concern with Venus and other celestial phenomena. Part of the inscription depicts zodiacal constellations, and its uppermost row is a sort of map of the constellations at the ‘base of the sky’ at the time of the Venus alignment. The Throne Inscription from Uxmal may now be recognized as one of the major sources of information about the pre-Columbian Maya zodiac.

The Maya haab, the 365-day solar year, ended with a 5-day period called “Uayeb.” According to Bishop Diego de Landa, preparations for the commencement of a New Year began during the Uayeb period of the preceding year. This paper concerns the events and ceremonies encompassing the beginning of a Cauac year and discusses the parallels between Landa's descriptions of these events and certain figures and activities portrayed in several almanacs of the Madrid Codex. Based on the calendrical structure of these almanacs, we argue that they pertain specifically to Uayeb-related ceremonies for a single year within the 52-year cycle, beginning on a day 13 Cauac.

The suggestion made early in this century that pages 43b to 45b of the Dresden Codex are concerned with the synodic cycle of the planet Mars was vigorously opposed in mid-century by J. Eric S. Thompson but supported during the last decade by other scholarship, including our own. Thompson’s interpretation, which Bruce Love has recently argued is correct, is certainly of historical interest and value, but it is no longer adequate in light of more recent advances in understanding codical instruments. In particular, it ignores the great importance to the authors of these instruments of the commensuration of calendrical and astronomical cycles. The Mars table is not just a Chac almanac dealing with weather and agriculture.

The recently discovered Tomb 12 at Rio Azul contains some evidence in support of my "zenith" reading for one of the collocations Closs reads as xaman, "north." A positionally literal reading of the astronomical glyphs associated with the directional collocations on the walls of that tomb is consistent with a directional system based on zenith and nadir, but not one based on north and south. Furthermore, Closs's reading does not account for the demonstrable na reading for the prefix in that collocation. On the other hand, his evidence for reading the second collocation as xaman is compelling, and the polyvalency of T566 seems well established.

A phonetic and semantic interpretation of the directional glyphs in Maya inscriptions and codices reveals that they did not refer to the cardinal directions. The glyphs that have been identified previously with north and south can be read phonetically as zenith and nadir, respectively. The glyphs for east and west refer semantically to the rising and setting sun. These data support Clemency Coggins's recent suggestion that Classic Maya directional symbolism was related to the path of the sun across the sky and through the underworld, rather than to the cardinal directions.

This paper describes some cases of inter- and intra-informant variability which cannot be explained in terms of social and contextual factors, and which do not seem to require probabilistic models to account for them. Analysis of several Zinacanteco speech taxonomies suggests that what are called variant responses are often only incomplete responses, and that if the cognitive system is represented as a taxonomy, then it is a taxonomy which is made up of a number of partial taxonomies, each of which is produced by a different informant or group of informants or by the same informant on different occasions. A frequently used method of ‘controlled eliciting’ is shown to be inherently incapable of guaranteeing the elicitation of complete taxonomies in every interview. For this reason, it is urged that before constructing a model of a cognitive system it is first necessary to establish what is ‘real’ cognitive variation by recognizing and eliminating that variation which results from methodological indeterminacy. (Ethnoscience, cognition, variability, methodology, controlled eliciting, folk taxonomy, speech, Maya languages.)