Here is a list of Public Holidays and main festivals in Thailand. Tourist attractions and shops, malls,  will be open as usual. All private and government offices are closed, including Embassies.

During Songkran, many attractions (but not all), businesses, government offices, Embassies, and many small shops will be closed. Shopping Malls will be open as usual. Just before and just after Songkran, all forms of transport are heavily booked up, and the majority of hotels will be fully booked.

Chinese New Year is a moveable festival each year, varying between late January and late March. Most Thai-Chinese owned businesses close, and transport is heavily booked, as are hotels. Other businesses, and governmen offices remain open. 

January 1 - New Years Day (plus 2nd January in 2012)

January 16 - Teachers Day (not a public holiday)

March 7  - Makha Bucha Day

April 13-15 - Songkran (Thai New Year)(plus 16th April in 2012)

May 1 - Labour Day

May 7 -Substitution Coronation Day  (Public Holiday)

May 13 - Royal Ploughing Ceremeny (not a public holiday)

June 4 - Wisaka Bucha Day

July 1 - Annual Bank Holiday (all banks closed, but not a public holiday) 

July 22 - Asanha Bucha Day

July 23 - Bhuddist Lent ( Government sector close and                                                 some private sector still operate)

August 12-13 - HM The Queen's Birthday

October 23 - Chulalongkorn Day

October 30 - End of Buddhist Lent

November 28 - Loy Krathong Fesival - Central Thailand, not a public holiday but a major evening festival.

  • During November close to Loy Krathong time , there are elephant round up festival in Surin. It is worth considering for those who want to join this event.

December 5 - HM The King's Birthday

December 10 - Constitution Day

December 31 - New Year's Eve.

If any day falls on a weekend an extra holiday is added, often (but not always) on the Monday after. 

 There are numerous regional and local festivals in addition to these.