In ancient times the date of Songkran varied according to the solar and lunar calendar. The word Songkran is derived from the Sanskrit language and means ‘move into’, referring to the orbit of the sun moving into each of the houses of the zodiac. In Thailand, the word Songkran has come to be identified specifically with the sun moving into Aries in April marking the end of a 12-month cycle and the beginning of a new solar year. These days the dates for the annual Songkran New Year Water Festival in Thailand are fixed for April 13-15. These dates are also a public holiday in Thailand. Some areas (such as Pattaya and Chonburi) have extended celebrations to include the Wan Lai Festival, but the official Songkran holiday dates throughout Thailand are April 13-15.