Thailand's Traditional Calendars

The first-time visitor to Thailand may register a bit of confusion as to why the timing of some important Buddhist and traditional holidays seems to 'float' across the calendar rather than occurring on fixed days each year as is customary in the West.The answer is such holidays are scheduled according to the ancient Thai lunar calendar, rather than the western Gregorian calendar which has been official in the Kingdom for many years.However, the traditional lunar calendar is very much in use for determining Thai holidays.Rural Thais still mostly count the date according to the phases of the moon, and Thai calendars distributed in rural areas commonly show both the western date together with the Thai lunar date.Astrologers also use lunar calendars to fix auspicious days for weddings, journeys, the dedication of a new house, and similar important occasions.




The Thai lunar calendar is divided into twelve months, like the western calendar, but the months are determined by the phases of the moon, not the position of the earth in relation to the sun.Being based on the phases of the moon, half of the lunar months are 28 days long and the other half are 29 days long.It is probable that the ancient Thai people based their lunar calendar on the yearly agricultural cycle as the most important aspect of their agrarian society.The first month of the lunar year was the month in which they began tilling the soil as that determined people's fortunes for the rest of the year the month was called Deuan Ai, which coincided with November or December of the western calendar.The ancient Thais most likely completed the agricultural cycle after the last month of the lunar year, Deuan Sip Sohng, which occurs in late October or early November of the western calendar and coincides with the bulk of the traditional rice harvest.The period of time between the end of the 12th lunar month and the beginning of the first month was the time of the new year.It was determined that the year ended on the last day of the twelfth lunar cycle and began again in the middle of the first cycle, leaving a gap of about 15 days.Thai lunar months are divided in half, based on the waxing and waning of the moon, called Keun and Raem respectively.Thais express the lunar date by naming the date of the waxing or waning half of the month followed by the number of the month, much as is shown in the chart below.This still does not clear up confusion as to why the lunar new year occurs in the fourth or fifth lunar month, but is easy to explain.When the ancestors of the modern Thais migrated from areas of Southern China their lunar calendar was based on the prevailing climatic cycle there.As the people moved further south the agricultural cycle started later and later in each new locale.As the agricultural cycle determined the succession of the lunar months, the changes in location caused adjustments in setting the beginning of the new year, and the new year holiday (Wan Troot), at the beginning of the fifth or sixth lunar month.The beginning of the fifth lunar month is now officially considered to be the Thai new year.The only problem with lunar reckoning is that the lunar year of 354 days is ten days too short.The Thais compensated for this by adding an extra month in the calendar every two or three years depending upon how out of sync the seasons and lunar months were, which achieves the same end as the cyclic insertion of an extra day in February for leap year.Confusion was increased by the fact the Lanna (northern Thai) lunar calendar started two months earlier than the Central Thai version -- the fifth month in Bangkok was the seventh in Chiangmai, which again was a result of differences in the agricultural cycle.The differing lunar calendars have been synchronized so there is only one set of holidays reckoned by the phases of the moon regardless of where you are in Thailand.The Thai lunar month was also divided into four weeks like the western model, but the progression of the weeks was determined by the rules determining the life of Buddhist monks.Four Buddhist Sabbath days (called Wan Pra or 'monks' day), like Sunday, are days of rest when devotees should go to the temple to hear the abbot's sermon and days when it is forbidden to slaughter animals for food.The day before wan pra was also a day of rest.Being the day the monks shaved their heads, it was called 'Wan Goan'.These two days comprise the Buddhist weekend.Interestingly enough, the modern Thai names for days of the week are direct translations of the western days.Monday is Wan Jaan, 'moon day', and the rest are similar.This effectively explains why the Thai new year occurs in the fifth lunar month, but little about the timing of the festival, Songgran.Songgran is a customary festival that grew out of the old new year celebration, Troot, a traditional time of relaxation.Occurring in the fifth lunar month, troot usually comes in late March or early April.In 1998 it is on Saturday, March 28.When Thailand adopted the western and Brahmin solar calendar, the date of Songgran was fixed on April 13th, which date coincides with a change in the Western Zodiac.Later, the space of time between the end of the Thai lunar calendar, wan troot, and the date set for Songgran on the Solar Calendar was deemed 'free time' as it did not belong to any particular year.The now popular Songgran water fights grew out of a traditional new year cleansing ceremony.The Thai lunar new year also signals the transition from one year to the next in the cycle of twelve animal named years which have astrological connotations.The Thai system is much like the Chinese except in Lanna where the year of the Elephant was substituted for the year of the pig in the Chinese and Central Thai systems.