Thais use both the Western Gregorian calendar and a Buddhist calendar - the Buddha is said to have died (or entered Nirvana) in the year 543 BC, so Thai dates start from that point: thus 2000 AD becomes 2543 BE (Buddhist Era). Dates for religious festivals are often set by the lunar calendar, so check specifics with TAT.

The most spectacular religious festivals include Songkhran (usually April 13-15), when the Thai New Year is welcomed in with massive public waterfights in the street (most exuberant in Chiang Mai); the Rocket Festival in Yasothon (weekend in mid-May), when painted wooden rockets are paraded and fired to ensure plentiful rains; the Candle Festival in Ubon Ratchathani (July, three days around the full moon), when enormous wax sculptures are paraded to mark the beginning of the annual Buddhist retreat period; the Vegetarian Festival in Phuket and Trang (Oct), when Chinese devotees become vegetarian for a nine-day period and then parade through town performing acts of self-mortification; and Loy Krathong (late Oct or early Nov), when baskets of flowers and lighted candles are floated on rivers, canals and ponds nationwide (best in Sukhothai and Chiang Mai) to celebrate the end of the rainy season. The two main tourist-oriented festivals are the Surin Elephant roundup (third weekend of Nov), when two hundred elephants play team games, and parade in battle dress; and the River Kwai Bridge festival in Kanchanaburi (last week of Nov and first week of Dec), which includes a spectacular son et lumiA?re at the infamous bridge.