[utkarsh858]

This reminds me of something. In Indian society, households have this calender called panchang. It is released annually by a group of priests who read and decipher ancient scriptures known as Vedas. Surprisingly panchang is quite accurate and informative about duration of solar and lunar eclipses.

[srean]

Nope they are not accurate anymore, have not been for a while. They used to be though. The model is similar to the Ptolemaic model but independently derived. If anyone cases the model is described in suryasiddhnta, English translations freely available.

The lack of accuracy of panchang is the result of accumulating calendric errors over centuries. Traditionally these used to get corrected by astronomical observations. However after the fall of Ujjain observatory the traditional / religious calendar has not been updated/corrected for centuries.

In fact right after independence India's first prime minister set up a calendar reform committee to update and modernise the traditional calendar. Top Indian scientists as well as scholars of Vedic scriptures were part of the committee.

To this day India government publishes these and updated positional astronomy records.

https://en.wikipedia.org/wiki/Indian_national_calendar