Lunar Year - 354.36 days long and divided by 12 lunar months known as adityas of 28 days each

Equinox - March 21 and September 23; sun rises and sets on a due east and west axis (north-south axis is 90 degrees off of the Equinox axis)

Spring Equinox - in Cambodia the spring equinox lasted for 3 or 4 days - the day of entry, day(s) of the "middle", and the last day. This marked the beginning of the new year.

Solstice - Sun rises and sets at the most southerly and northerly points on the horizon

Summer Solstice - most northerly point of sun rise and set occurs on June 21st

Winter Solstice - most southernly point of sun rise and set occurs on December 21st

Sun and Moon Movement - together these move approximately 54 degrees north and south during the year in this region of the world

Aguila - a constellation with symbolism to the eagle; in Mesopotamia is also is in the form of the solar god Zamama and the god Ninip, another solar god; the star Altair is a major element of this constellation

Lunar Months - A lunar month is 27.3 days; 27 days, 7 hours, and 43 minutes. Depending on the month, for 14 or 15 days the moon increases in size as it riser closer and closer to the eastern horizon. At the time of the full moon, the moon rises in the east at sunset and for 14 or 15 days begins to rise further and further westward as it steadily wanes. Finally, it is no longer visible on the western horizon and the cycle begins again. To Khmer, these two opposite patterns were called the light and dark halves of the lunar month. Like the 12 adityas or lunar months, the Khmer reconsigned 24 half-months connected with specific deities and constellations.

Zodiac - Mesopotamian astronomers divided the sky into 10 degree units - one for each of the signs of the zodiac for a circle of 120 degrees. Around 650 B.C. there was a set of 12 northern constellations above the zodiac given a 60 degree circle and a set of 12 constellations below the zodiac given an 240 degree circle. For the Khmer, there were 12 zodiac signs with 10 degrees for each sign for a total of 120 degrees.

The moon is symbol in many cultures representing the female. The cycle of the moon is often conceived of as a parallel to the menstrual cycle which also runs about 27 or 28 days on average

The Khmer associated the spring equinox with the east, the summer Solstice with the north, the south with the winter Solstice, and the west with the fall equinox. This counterclockwise path was divided into 12 major sections - the 12 solar months. The individual day could be divided as well into its various parts. The Khmer further associated a series of god with each direction.

When the new moon begins the month, the sky is black for one or two nights; then the slowly waxing crescent moon is seen just over the western horizon after sunset. About 12 days later, the full moon rises in the east. After the full moon, there are 14 more days until we are back to zero again.