Why Every Thai Festival Date You Read in January Is Wrong
Most of the country's holidays follow the moon, which is why the Songkran date moves and why a guide written in 2023 is wrong about 2027.
I told a host to expect me on the first day of Songkran and arrived on a Tuesday, in the middle of an ordinary working week, while a million people were celebrating a water festival three days away. She was extremely polite about it and I noticed the error exactly four hours later.
The date was not wrong. It was correct for a different year.
Last verified 5 October 2026.
Why the dates move
Most of Thailand's religious calendar is lunar, and a lunar calendar cannot be mapped onto a fixed grid of Gregorian years. The new moon shifts, and everything keyed to it shifts with it.
So the most important thing to understand is that a date you read in an article is only true for the year that article was written, and that this applies with particular force to anything involving a full moon, which is most of the interesting calendar.
Songkran, Loy Krathong, Makha Bucha, Visakha Bucha, Asalha Puja and the Buddhist Lent all move. The public holidays tied to them move with them, which means the government holiday calendar for a given year is genuinely different every year, and an office closure date you planned around three years ago is not evidence of anything.
The two calendars and the gap
There is also a years-of-the-rat convention. The Thai year is counted as an animal year in a sixty-year cycle, and the cycle repeats every twelve years, which is why two people born twelve years apart have the same animal and a birthday that is a shared joke for the rest of their lives.
And the Buddhist Era is in use alongside the Christian one, which is a five hundred and forty-three year offset in the year of writing, and the reason Thai dates carry three numbers and appear to be from the future.
None of this is confusing if you know which is which, and all of it is confusing if you do not, and the mix appears on every official document you will sign here.
The days that actually matter
Makha Bucha, on the fifteenth day of the third lunar month, marks the spontaneous gathering of the Buddha's followers and it is a public holiday with temple ceremonies and candle processions that go out in the evening.
Visakha Bucha, in the sixth month, is the birth, enlightenment and death of the Buddha in one date, and it is the single most important day in the Thai Buddhist year. Temples are busy all day and the evening candle procession is the thing to see.
Asalha Puja, in the eighth month, is the first sermon, and it is the opening of Buddhist Lent, which is a real and observable period in the country: monks stay in the temple, and ordination ceremonies happen.
Loy Krathong is the floating of baskets on water on the full moon of the twelfth month, and it is the one that fills Chiang Mai with people in the river and a great deal of fireworks.
And Songkran, in April, is the fixed one. It is keyed to the solar calendar in mid-April, which is why it is the exception to everything above and why my mistake was more embarrassing than it looks.
What this means practically
Plan temple days with a Thai calendar or a local calendar app, not with a date you read somewhere, and check the year. The single most common booking error I see is a visitor booking a flight for a ceremony that happens on a different day than the guide said.
Temples are busiest on the holy days and closed or quiet on ordinary ones, so getting this right changes what you see, not just whether you can get there.
And the public holiday consequences are the practical version of the same fact: immigration offices close, government departments shut, and the date list is genuinely different every year. We have covered the shutdown problem in the public holidays article; the reason it catches people is this one.
