Here, by Lake Atitlan in Guatemala, approximately 15 degrees north of the equator we observe the phenomenon of the solar zenith twice per year, but what is the solar zenith?
The zenith point is the highest point of the sun in the sky. This will occur at midday, when the sun crosses an imaginary line running from north to south known as the meridian. The path of the sun through the sky is called the ecliptic, and is also the line on which you can find the planets – it is the plane of the solar system. At the days of solar zenith, the meridian and the ecliptic will form a perfect cross at midday, with 90 degree angles in each quadrant. This means that the sun will be directly overhead, and our shadow, if we stand up straight, will be just a little puddle around our feet. The sun is perfectly balanced on both the east/west and north/south axes.
This phenomenon happens at all locations within the tropics, and at slightly different times. On the Tropic of Cancer, 25.4 degrees north of the equator, solar zenith is observed on just one day of the year, June solstice. The further south you go, the further the the difference in days increases up until you reach the equator, where the solar zenith occurs on the equinoxes. If you continue south to the Tropic of Capricorn, 23.4 degrees south of the equator, you find that again the solar zenith occurs only once, on December solstice.
For us here, it means that in the days between the first zenith transit at the end of April and the second in August (around August 11), the sun is effectively in the north at midday. It is not by a great amount (about 81 degrees above the northern horizon at midday) but it can certainly mean that planning a garden is not so easy.
Perhaps one of the most interesting things about the solar zenith is that the two occasions are 105 days apart. If we use the Mayan solar calendar, they count the solar year with 365 days. Therefore the “summer” period between the April and August zenith transits of 105 days means that the remainder of days, between August and April works out to 260 days, the number of days in the sacred calendar. This is a fact which convinced some scholars that the sacred calendar must have originated at a latitude of about 15 degrees north of the equator. There is also some other special Mayan numerology in the timing of the zenith passages, with each one occurring 52 days away from the June solstice – 52 being a number which occurs many times in Mayan mathematics. It is also interesting that the second zenith transit occurs around 11th August, which according to the GMT correlation, was the day of creation of the fourth age of the Sun back in 3114BC.
We can tell by the alignments of certain structures (for example El Caracol at Chichen Itza, The Palace at Palenque and stelae 10 and 12 at Copan to name just a few) that the ancient Maya were marking the sunrises and sunsets on zenith days, so it would seem that zenith days were of importance to them. There are also zenith tubes, long, vertical holes which could only illuminate the chamber below when the sun was directly overhead on zenith days.
Exactly what meaning was attributed to the zenith days is something I have yet to understand. However, there is a great deal of evidence that the April zenith day was seen as a day for general planting to start. Right now we are waiting for the rains to come. A few little sprinkles have happened to wet the earth up a bit, but the true rains are on their way. With this zenith coinciding with the days 13 Kej and 1 Q’anil, it would seem like an excellent time to connect with the spirit of the natural world and the ancestors (13 Kej) and plant your seeds for an abundant harvest (1 Q’anil) asking the sun to bless your crops.