In 1940, Thailand moved its New Year's Day to January 1st. The old New Year is still a holiday
called Songkran. Years are counted as the Buddhist era (B.E.) which started 543 years before the
Christian era (A.D.). To calculate the Buddhist year simply add 543 to the present Christian year
and vice versa. So 2009 A.D. plus 543 is the year 2552 B.E.