iVillage

We have mostly been describing the lunar months in this book, which are measured from the moment of New Moon to the succeeding New Moon. These months, as we have pointed out, do not neatly match up with the standard solar calendar month.

We should differentiate between lunar months and the solar month or what are called the ‘solar terms.’ Solar months have to do with the passage of the Sun through the tropical zodiac, and the first solar term or solar month is called by the Chinese the ‘Beginning of Spring.’ In Chinese and Tibetan astrology, it begins the moment the Sun reaches 15 degrees of the tropical zodiac sign Aquarius (15 degrees Aquarius), which takes place somewhere around February 4th or 5th each year. From the Chinese point of view, the familiar vernal equinox (0 degrees Aries) is the middle of spring, not the beginning.
As mentioned, lunar and solar months do not neatly match, and the number of lunar months in a solar calendar year (Gregorian calendar) are more than the standard twelve calendar months we all know. The net result is that every 32.5 lunar months, these extra lunar days accumulate to the point that an extra (intercalary) month has to be added to that year’s calendar. Just as we occasionally add an extra day at the end of February in the solar, an extra month is added every few years.

Another point to keep in mind is that the Tibetans use the mean longitude of the Sun for their calculations, and not the true longitude that astronomers would use.

This has been a quick overview. I have tried here to point out a few of the calendar concepts that concern the Tibetan astrologer—some of the problems. It would take most of a book just to define what these problems are and how best to view them. Luckily that book exists in Edward Hennings ‘Kalachakra And the Tibetan Calendar.’ Please see that book for a very thorough explanation of these matters.