Hindu tradition following the decline of Buddhism in India. It was in widespread use by the 6th to 7th centuries, e.g. in the works of Varāhamihira and Brahmagupta, and by the 7th century also appears in epigraphy in Hindu Southeast Asia. The calendar era remained in use in India and Southeast Asia throughout the medieval period, the main alternative era in traditional Hindu timekeeping being the Vikram Samvat era (56 BC). It was used by Javanese courts until 1633, when it was replaced by Anno Javanico, a hybrid Javanese-Islamic system. It was adopted as the era of the Indian national calendar (also known as "Śaka calendar") in 1957 but not widely used. The Shaka epoch is the vernal equinox of the year AD 78. The year of the official Shaka Calendar is tied to the Gregorian date of 22 March every year, except in Gregorian leap years when it starts on 21 March. The Lunisolar Shalivaahana Saka continues to be used widely in Southern and Western India for many religious and some secular purposes such as sowing and agriculture. See also Vikram Samvat Indian national calendar Gregorian calendar Rudrasimha I References Citations Sources Hindu calendar Calendar eras