Mission

To make the astronomy of the Hindu pañcāṅga universally known and clearly understood by the Hindu community worldwide.

With understanding, comes appreciation.

Purpose

The Hindu calendar, aka pañcāṅga, is used only for religious purposes today, but this was not always so. Before the Gregorian calendar was universally adopted, the Hindu calendar was used all over India for religious and civil purposes.

The Hindu calendar defines a number of calendric elements, such as māsa, pakṣa, tithi, varṣa, ayana, ṛtu, etc. These definitions are entirely based on astronomy, specifically the movement of the Sun and the Moon.

While the calendar, which was kept alive by Hindu religious institutions, has survived over millennia, the astronomy has been forgotten.

Our goal is to revive the understanding of the astronomical basis of the Hindu calendar.

Founder's Message

The Hindu pañcāṅga is an almanac used by the Hindu community worldwide to regulate the performance of religious rites. Pañcāṅga are published by religious establishments and are used by priests to advise lay people. Most of us have little understanding of how to read and use the pañcāṅga; we consider it a purely religious document which only priests can comprehend.

Our culture is replete with astronomical references. Consider the following:

Celestial Names: We name our children after the stars. Names like Ashwini, Rohini, Chitra, Swati, and Revati are not merely traditional; they are the names of the nakṣatra that define our sky.

The Navagraha: Every Hindu temple houses a shrine to the nine major celestial bodies. Devotees circumambulate representations of the Sun (sūrya), Moon (candra), the five visible planets—Mercury (budha), Venus (śukra), Mars (maṅgala), Jupiter (guru), Saturn (śani)—and the lunar nodes (rāhu and kētu), acknowledging our place within the solar system.

Vedic Rituals: During wedding ceremonies, the double star Arundhati and Vashistha is pointed out to the newlyweds—a beautiful astronomical metaphor for an inseparable bond.

Divine Visions: In sacred lore, the infant Krishna reveals his divinity to his mother, Yashoda, by displaying the entire cosmos within his mouth. Similarly, Lord Shiva is worshipped as Chandra-mouli, the one who wears the Moon in his topknot.

Lunar Metaphors: The legend of the Moon and his twenty-seven wives is a vivid allegory for the Moon's sidereal journey across the twenty-seven segments of the ecliptic, providing a mythic explanation for the lunar phases.

Yet, a culture that internalised astronomy to such an extent has now forgotten the science of astronomy. The good news is that the pañcāṅga has survived even though the astronomy has been lost. The time has come to recover that lost science and re-establish the relevance of the Hindu calendar.

S. Kishore Kumar

Science Communicator

Former Sr. Vice President

Siemens Healthineers

@Ahargana

youtube.com/@ahargana

A masterclass on the astronomy of the Hindu calendar

Each episode of this YouTube channel highlights one calendric element of the Hindu calendar. All episodes are built around Stellarium simulations of the orbital movement of the Sun, Moon and the planets, with the Surya Siddhanta - a canonical astronomical text - as the basis.

The use of modern-day software simulations bridges the 1500-year gap that separates the ancient from the modern. It also confirms that the ancient astronomical concepts remain valid to this day, across a span of a millennium and a half!

Bhavna Roy

Author, Philanthropist, and Educator

"I have read a lot on the Surya Siddhant, but the one podcast that gave me so much knowledge on the Surya Siddhant is Kishore Sridhar Kumar's Ahargana. I got addicted to that YouTube channel. It's his own YouTube channel, and he has explained the Surya Siddhant visually so simply so simply in, I think, over 20 - 23 episodes. It's really worth watching. Binge on that, as I did."

Student Outreach