time, calendar, and cosmology
What is the Hindu calendar?
How it works
The Hindu calendar is called a lunisolar calendar because it follows both the moon and the sun. The months are based on the moon's cycle. Each month begins either at the new moon or the full moon, depending on the regional tradition. At the same time, the calendar is adjusted to stay in step with the solar year, so that seasons and festivals do not drift too far over time. This is done by adding an extra month every few years. That extra month is called an intercalary month, sometimes known as Adhik Mas.
What it is used for
The main purpose of the Hindu calendar is religious and ceremonial. It sets the dates for festivals like Diwali, Holi, Navratri, and Janmashtami. It also guides life-cycle rituals, from birth ceremonies to weddings to the timing of last rites. Each day carries a set of qualities based on the lunar day, the day of the week, the position of the moon, and other factors. Together these are used by priests and families to find auspicious timing for important events. This system of auspicious timing is called muhurta.
Regional differences
There is no single Hindu calendar used everywhere. Different regions of India have their own versions, with different names for months and different starting points for the new year. The new year falls at different times in different traditions, which is why Ugadi, Gudi Padwa, Vishu, and Baisakhi are all new year celebrations in different parts of the country. Some communities start the month at the new moon, others at the full moon. The names of the twelve months are shared across many versions, but their feel and use can vary quite a bit from place to place.
Time in a larger sense
The Hindu view of time goes far beyond a single year. The tradition holds that time moves in vast cycles called yugas, which build into even larger cycles called kalpas. These are enormous spans of time covering the rise and fall of whole worlds. The calendar used in daily life sits inside this much bigger picture. Even the small rhythms of a day, a month, and a year are seen as part of the same cosmic order.
Today
Most Hindus around the world use the Gregorian calendar for work and daily life. The Hindu calendar runs alongside it, mainly for religious purposes. Printed almanacs called panchangam give daily details used by priests and families to plan ceremonies. Apps and websites now make it easy for people in the diaspora to check festival dates, auspicious days, and tithi, the lunar day, wherever they live.