Hindu calendar

Hindu calendar is a collective name for most of the luni-sidereal calendars and sidereal calendars traditionally used in Hinduism.

The Hindu calendars have undergone many changes in the process of regionalisation. Some of the more prominent regional Hindu calendars include the Nepali calendar, Punjabi calendar, Bengali calendar, Odia calendar, Malayalam calendar, Kannada panchangam, Tulu calendar, Tamil calendar, Vikrama Samvat used in Northern India, and Shalivahana calendar in the Deccan States of Karnataka, Telangana, Maharashtra and Andhra Pradesh. The common feature of many regional Hindu calendars is that the names of the twelve months are the same (because the names are based in Sanskrit). The month which starts the year also varies from region to region. It is now 2059.

The Buddhist calendar and the traditional lunisolar calendars of Cambodia, Laos, Myanmar, Sri Lanka and Thailand are also based on an older version of the Hindu calendar.

Most of the Hindu calendars derived from Gupta era astronomy as developed by Āryabhaṭa and Varāhamihira in the 5th to 6th century. These in turn were based in the astronomical tradition of Vedāṅga Jyotiṣa, which in the preceding centuries had been standardised in a number of (non-extant) works known as Sūrya Siddhānta. Regional diversification took place in the medieval period. The astronomical foundations were further developed in the medieval period, notably by Bhāskara II (12th century).