Non-statutory holidays are written in gray.
Moving Holidays in Thailand
Moving holidays with (so far and for us) uncalculatable dates:
The Thai Lunisolar Calendar
The historical Thai calendar is basically a lunar calendar, according to which the beginning of a month is always based on a new moon. A month therefore has about 29.53 days. So that a month does not end in the middle of the day, the length of a month varies, as in most cases, but alternately 29 or 30 days. In the seventh month, this rule is reversed, so that the seventh month always has as many days as the sixth month. This also changes the number of days in all equal months of the following year:
In order to consider the course of the sun, complex calculations are used to insert a leap day or even a whole leap month every few years. The eight month of a year is simply doubled. A year thus does not always 12 months, but is also 354, 355 or 384 days long. This alone makes it difficult to map the beginning of the year to the Greogian calendar.
The holidays calculated according to this lunar calendar are Makha Bucha, Visakha Bucha, Asalha Puja, Khao Phansa, Sat Thai, Ok Phansa, the Kathin ceremony and Loi Krathong. Most of these ceremonies are held during full moon, only Sat Thai is celebrated on the day of the new moon. Since 1888, this calendar system has only been used to calculate holidays. Except for the year, the Thai calendar has corresponded to the Gregorian calendar since then.
Songkran, the Thai New Year festival
The Thai calendar is very complex, even for Thais themselves. On the other hand, the celebration of the beginning of new year has nothing to do with the beginning of the first month on the calendar, but with the equinox in spring, i.e., the equinox of day and night, where day and night have about the same length. For the sake of simplicity, this festival is always set to the three days, beginning on April 13th.