Editing Maya calendar (section)

==819-day count==
Some Mayan monuments include glyphs that record an 819-day count<ref>{{cite news  |title= The Mayan mystic 819-day calendar |trans-title=The Mayan mystic 819-day calendar |url= https://mexicanroutes.com/the-mayan-mystic-819-day-calendar/ |publisher= Mexican Routes |date=2024-12-26 |accessdate=27 Dec 2024 |language=English }}</ref> in their Initial Series. These can also be found in the [[Dresden Codex|Dresden codex]].<ref>Grofe, Michael John 2007 The Serpent Series: Precession in the Maya Dresden Codex page 55 p.&nbsp;206</ref> This is described in Thompson.<ref>Maya Hieroglyphic Writing 1971 pp.&nbsp;212–217</ref> More examples of this can be found in Kelley.<ref>Decipherment of Maya Script, David Kelley 1973 pp.&nbsp;56–57</ref> Each group of 819 days was associated with one of four colors and the cardinal direction with which it was associated{{snd}} black corresponded to west, red to east, white to north and yellow to south.

The 819-day count can be described several ways: Most of these are referred to using a "Y" glyph and a number. Many also have a glyph for Kʼawill{{snd}} the god with a smoking mirror in his head. Kʼawill has been suggested as having a link to Jupiter.<ref>Star Gods of the Maya Susan Milbrath 1999, University of Texas Press</ref> In the [[Dresden Codex|Dresden codex]] almanac 59 there are [[Chaac]]s of the four colors. The accompanying texts begin with a directional glyph and a verb for 819-day-count phrases. Anderson<ref>{{cite web|url=http://www.traditionalhighcultures.org/819-Day-Count_&_Y_Glyph.html |archive-url=https://web.archive.org/web/20150506025253/http://www.traditionalhighcultures.org/819-Day-Count_%26_Y_Glyph.html |archive-date=May 6, 2015 |title=Lloyd B. Anderson The Mayan 819-day Count and the "Y" Glyph: A Probable association with Jupiter |publisher=Traditional High Cultures Home Page |access-date=March 30, 2015 |url-status=dead }}</ref> provides a detailed description of the 819-day count.

=== Synodic periods of the classical planets ===

    Moon: 1 x 819 + 8 days = 28 (synodic 29.53 d) "28 months"
    Moon: 4 x 819 + 2 days = 111 (synodic 29.53 d) "111 months"
    Moon: 15 x 819 + 0.3 days = 416 (synodic 29.53 d) "416 months"

    Draconic: 31 x 819 days = 933 (draconic 27.21 d) "nodal months"

    Mercury: 1 x 819 + 8 days = 7 (synodic 115.88 d)
    Mercury: 15 x 819 + 2 days = 106 (synodic 115.88 d)

    Venus: 5 x 819 + 8 days = 7 (synodic 583.9 d)

    Sun: 4 x 819 + 11 days = 9 (synodic 365.24 d) "9 years"
    Sun: 33 x 819 + 1 days = 74 (synodic 365.24 d) "74 years"

    Mars: 20 x 819 + 2 days = 21 (synodic 779.9 d)

    Jupiter: 1 x 819 + 21 days = 2 (synodic 398.88 d)
    Jupiter: 19 x 819 + 5 days = 39 (synodic 398.88 d)

    Saturn: 6 x 819 - 1 days = 13 (synod 378.09 d)

<ref>2023, John H. Linden, Victoria R. Bricker, The Maya 819-Day Count and Planetary Astronomy https://doi.org/10.1017/S0956536122000323</ref>