8800 Years Old Indian Calendar of Mayasura's Surya Siddhanta - A Documentary by Vedveer Arya

Software simulations using the JPL Horizons Ephemeris System of NASA establish that the conjunction Mayasura recorded occurred only once in the last 16,000 years, on 22 February 6778 BCE.

Spherical trigonometry is a sine qua non for astronomical calculations and predictions. (It was later refined with Calculus). Astronomy became an essential part of early Indian civilization for both planning agrarian operations and making predictions based on horoscope. It was Mayasura’s Surya Siddhanta, which had revolutionised Indian astronomy by introducing precise astronomical calculations in its calendar.
Mayasura has recorded observing the Sun, Moon and all planets in conjunction in Aries (Mesha) on new moon day of Chaitra month at the end of the 28th Krita Yuga in his Surya Siddhanta.
Software simulations using the JPL Horizons Ephemeris System of NASA establish that such conjunction has occurred only once in the last 16,000 years, on 22 February 6778 BCE (see picture).
Mayasura (who lived thousands of years before) and not Greek astronomer Hipparchus (2nd century BC) should be reckoned as the rightful father of trigonometry.