Why so many older Thais celebrate their birthday on January 1
In the old days in Thailand, before they issued certificates of live birth at birth, the date of birth was first recorded when the child went to school or required a government document of some kind. At that point the parents were asked to declare a date of birth and, as was usual, if the parents could not remember the exact date, they were asked to simply declare the birth year and the birth date was then recorded as January 1 of that year. That is why so many older Thais celebrate their birthday on New Year's Day. Only now you know-ho the wrrest of the story.