Calendar conversions sites (JD to Gregorian and vice-verse; Mayan to Gregorian, etc.:

Felix Verbelen's Ancient Astronomy site. Includes dates of Venus helical rise and set for 20 deg N and AD 800-1600.

Julian Date to Julian/Gregorian and vice-versa

Julian date calculator from U.S. Naval Observatory

Mayan Calendar Tools. Uses 584,285 correlation for conversion.

"The periods of the Maya History"

Selected pages from the Dresden Codex. From J.E.S. Thompson, A Commentary on the Dresden Codex

Three pages from the Codex Borgia

The following illustrations are taken mostly from Morley, Bureau of American Ethnology, Bulletin #57 (An Introduction to the Study of Maya Heiroglyphs, Dover Reprint), and from Aveni, Skywatchers of Ancient Mexico



"Leyden Plate", Guatematla, Aveni, p. 145

Glyph(s) "G", Aveni, p. 164.

C, D, and A glyphs (Aveni)

Aveni, p. 166. Stela A, Copan, Stela 3, Tikal, House C, Palenque, Stela E, Quirigua'

P. 168, Aveni. Lintel of the Initial Series, Chichen Itza', Temple of the Foiated Cross, Palenque, Temple of the Sun, Palenque


Many of the following images are from Aveni, Skwatchers or Aveni, Skywatchers of Ancient Mexico

Chichen Itza:

El Castillo at Chichen; 91 steps on each side x 4 =364 day computing year; Calendar Round features. Photo RDP

El Castillo

Serpent heirophany

The Caracol ("snail") at Chichen Itza'

View of west face of the Caracol; see the plan below

Plan of the Caracol

Plan of west facing windows in the Caracol, Chichen Itza'

View through windows in the Caracol; see Aveni


All Uxmal photos by RDP unless otherwise credited

Facade of the Palace of the Governors, Uxmal. Venus imagery.

Facade of Palace of Governors, showing Zodiac--Brickers...

The next two images are views from the front of the Palace of the Governors, Uxmal; see Aveni.

Photo RDP

Courtesy Aveni

Other sites:

Building J at Monte Alban, Oaxaca

Zenith tube at Monte Alban

Uaxactun; see Aveni

View from Temple 22 toward Venus setting, at Copan


Pyramid of the Sun at Teotihuacan as see from Pyramid of the Moon

Street of the Dead, looking approximately south from the Pyramid of the Moon

Looking toward western horizon from Pyramid of Sun, perpendicular to west face; see Aveni, Skywatchers