Cosmic Mandala

Tibetan Lunar Calendar

Cosmic Mandala

Nowhere is the importance placed on the moon more evident in Tibetan astro science than in the lunar calendar. This unique system plays a central role in Tibetan culture, allowing for the calculation of dates for various ceremonies. As with all lunar calendars, the 29.5 day synodic cycle creates some obvious difficulties, which have multiple creative solutions. Therefore, the Hindu, Tibetan, and Chinese lunar calendars are not synonymous, and offer unique opportunities for students to compare and contrast these systems.

In Buddhist and Hindu systems, the full moon must fall on the 15th day of any month, and the new moon on the 30th. Both the 29.5 day synodic cycle and the fact that the moon rises at a different time each day lead to differences between these systems (and among Buddhist traditions) as to when a specific lunar day actual begins and ends. The Tibetan calendar uses skip days (tsi chad-pa) and doubled days (tsi lhag-pa) to reconcile the differences between the solar and lunar cycles. Therefore a particular month might have two 19ths and no 23rd. In addition, approximately every thirty months a full month is added to keep the calendar aligned with the seasons (in contrast with the Islamic calendar, which is a truly lunar calendar). The rules for calculating the Tibetan calendar are complex, and passed down from master to student. One result is that Losar, Tibetan New Year, and Chinese New Year do not always correspond, but can differ by an entire lunar month. As the traditions surrounding Losar are as rich as those of the Chinese New Year, multicultural lesson plans centered on Chinese New Year can be effectively adapted to parallel lessons for Losar, and would teach similar concepts.

Particular days of any given month are given special significance, either for good or bad. For example, the 8th day of each lunar month is considered an auspicious day for making offerings to the female buddha Tara. In general, the waxing half of the lunar month is generally considered more auspicious than the waning part of the month. Therefore it is better to begin projects near the beginning of the month so that they can increase with the waxing of the moon. The most important date of the Tibetan year is Saga Dawa, the anniversary of Buddha's birth, enlightenment, and passing away. This falls on the 15th day of the 4th month. It should be noted that the months are signified by numbers, not names.

A second calendar is used in Tibetan rituals, the Kalachakra calendar, whose New Year falls at the beginning of the third month. Therefore if Losar is in February, the Kalachakra New Year is in April. The difference derives from the fact that when the Tibetan calendar was introduced into Mongolia in the 13th century, adjustments were made in the calendar to align it with the Mongolian months, a change that was adopted in Tibet as well. The Kalachakra calendar begins in reference to the sun (when the sun is in Aries, which makes the date closer to the Spring equinox).

Similar to the Chinese calendar, each year is assigned to a particular animal and element. With twelve animals and five elements, there is a natural 60 year cycle called a Rab-byung that results. The twelve animals are:


For example, 1995 was the Wood-pig year and 1996 was the Fire-mouse year. 2009 is the Earth-ox year. It is believed that every 12 years a person will experience a time of greater obstacles. Particular prayers and ceremonies are generally done in order to counteract these obstacles.

Sample calendars for recent months can be downloaded for classroom use here .


For more information, consult the following websites: