| "The Mayan Venus calendar is best
known from a table in the Dresden Codex (Thompson
1972:62-71), but the presence of Venus reckoning in the
Guatemalan highlands is attested by the PV and by a
Quiché almanac dating from 1722 (Berendt n.d.). A given
Venus synodic period (lasting 584 days) is divided into
four stages, with Venus appearing as the morning star at
the beginning of the first stage and remaining visible
throughout it (236 days or 8 synodic moons).
During the second stage (90 days),
Venus goes through its last 27 days (one sidereal moon)
as the morning star, disappears for 50 days, and runs
through its first 13 days as the evening star. It
remains visible as the evening star thoughout the third
period (250 days) and stays out of sight throughout the
fourth period (8 days), after which it returns to the
first stage.
During a given 584-day period the 20
day names repeat 29 times, giving 580 days with a
remainder of 4; this means that a Venus cycle will
always begin 4 days later in the sequence of 20 day
names than the previous cycle.
And since 20 is evenly divisible by 4
(20 / 4 = 5), only 5 of the day names can ever begin a
Venus cycle. In the Dresden Codex the chosen days (here
given their Quiché names) were Junajpu, K'at,
Q'anil, E, and Ajmak, followed by
Junajpu again.
Starting from 1 Junajpu (as the
Dresden Codex does) and running through five complete
periods so as to show all of the possible day names, the
beginning dates for the four stages within each Venus
period work out as follows:
|
DATES FOR
FIVE SUCCESSIVE VENUS PERIODS |
| |
First |
Second |
Third |
Fourth |
Fifth |
|
Appearing as morning star: |
1 Junajpu |
13 K'at |
12 Q'anil |
11 E |
10 Ajmak |
|
Becomes invisible: |
3 Ajmak |
2 Junajpu |
1 K'at |
13 Q'anil |
12 E |
|
Appears as evening star: |
2 Kame |
1 Tz'i' |
13 Ix |
12 Tijax |
11 Iq' |
|
Becomes invisible: |
5 Ajmak |
4 Junajpu |
3 K'at |
2 Q'anil |
1 E |
After five complete
cycles totaling 2,920 days, the movement of Venus
fill eight idealized years of 365 days each and come
within hours of spanning 99 lunations. At this point
Venus begins repeating the same series of
period-beginning day names but with different
numbers, while at the same time coming very close to
repeating its relationship to the fixed stars and
the seasons of the solar year. To get back to a
morning star appearance on 1 Junajpu, Venus
must repeat the full set of five periods a total of
thirteen times." (Popol Vuh)
|