New Year's Day - Jan 1st
Public holiday. Even if the traditional New Year is celebrated in April (Songkran Festival), the year changes on January 1st. Thai people start counting the years from Buddha's birth, 543 years before Jesus Christ, but they also use the western calendar. So year 2015 is more commonly referred to as year 2558. If you are in Bangkok, the countdown usually takes place at the World Trade Center (Chidlom BTS station).