Songkran is a term derived from the Sanskrit word, saṅkrānti (or, more specifically, meṣa saṅkrānti) and used to refer to the traditional New Year celebrated in Bangladesh, Thailand, Laos, Cambodia, Myanmar, Sri Lanka, parts of northeast India, parts of Vietnam and Xishuangbanna, China. It begins when the sun transits the constellation of Aries, the first astrological sign in the Zodiac, as reckoned by sidereal astrology. It is related to the equivalent Hindu calendar-based New Year festivals in most parts of South Asia which are collectively referred to as Mesha Sankranti.