The date of the festival was originally set by astrological
calculation, but it is now fixed. If these days fall on a
weekend, the missed days off are taken on the
weekdays immediately following. If they fall in the middle
of the week, many Thai take off from the previous Friday
until the following Monday. Songkran falls in the hottest
time of the year in Thailand, at the end of the dry season.
Until 1888 the Thai New Year was the beginning of the
year in Thailand; thereafter 1 April was used until 1940.
1 January is now the beginning of the year. The
traditional Thai New Year has been a national holiday
since then.