Vedic Hindu Calendar : the Most Ancient Lunar Calendar System (Part 1)

The Vedic Hindu Calendar differs the western (Julian and Gregorian) calendars in many respects. It is based on the Vedic astronomy (Hindu Vedanga Jyotisha). The Rig Veda (1.154.48) and Atharva (X, 8) mention the lunar calendar system. Vedic Hindu calendar system measured time with the use of tropical zodiac arc and the four Cardinal Poles of Equinoxes and Solstices. The Vedic texts such as Brihad Samhita were able to calculate the most accurate timings for Equinoxes and Solstices. The Equinox of March (zero degree of the ecliptic when days and nights are equal) marks the beginning of the Vedic year. Similarly December Solstice marks the beginning of Uttarayana (Makar Sankranti).

Salvahana Saka

King Salivahana revised the Vedic Calendar and introduced in the year 78 AD (Corresponding calendar year). The calendar system bears his name and called as Salivahana Saka (era). Thus the current Salivahana year 1931 corresponds to the year 2009 AD.

Vedanga Jyotisha

The Vedanga Jyotisha, which dates back to 1350 BC, was preached through the word of mouth to his disciples by Sage Lagadha, an astronomer cum mathematician. The sage was able to prescribe formulas and rules to track the motions of the sun and the moon. Vedanga Jyotisha is considered as fundamental text to Vedic Hindu Calendar.

Surya Siddhanta

Surya Siddhanta (dates back around 400 AD), another ancient Sanskrit text of astronomy, standardized the Vedic concept of time. We cannot ascertain the author of this text. It is one of the oldest surviving texts on astronomy. This Vedic text is considered as the treatise on astronomical zodiac configurations. The mathematical wisdom of applying sine, cosine and inverse sine functions to tabulate the zodiac arc makes the modern mathematicians spell bound. The text with remarkable accuracy prescribes the Hindu Time Cycles which include:

1. vinadi (six human respirations),
2. nadi (60 nadis),
3. sidereal day (sidereal day and night),
4. lunar day (thithi),
5. month (30 sidereal days),
6. solar month,
7. lunar month and
8. Samvatsara or year (12 solar or lunar months)

The text also talks about the four yugas or epoch:

1. One year is equal to one day for Deva;
2. 360 Divine days constitute one Divine Year;
3. 12000 Divine Years constitute one Chatur (four) Yuga;
4. 1000 Chatur Yugas constitute one Kalpa;
5. two Kalpas constitute one Bramha's day.

The Chtur yugas or the four epochs:

1. Satya Yuga,
2. Treta Yuga,
3. Dwapar Yuga and
4. Kali Yuga.

Satya Yuga, the first among the four epochs lasted for 4000 Divine years. The second epoch Treta Yuga lasted for 3000 Divine years. The third epoch Dwapara Yug lasted for 2000 Divine years and the fourth and current epoch Kali Yuga will last for 1000 Divine Years (i.e., Corresponding 432,000 earthly years).

Reference Sources:

1) Gregorian Calendar http://en.wikipedia.org/wiki/Gregorian_calendar

2) Significance of the Tamil New Year http://forumhub.mayyam.com/hub/viewlite.php?t=1767

3) Surya Siddhanta http://www.absoluteastronomy.com/topics/Surya_Siddhanta

4) Vedanga Jyotisha http://en.wikipedia.org/wiki/Vedanga_Jyotisha

5) Western - Vedic Calendars Western/ Hindi/ Tamil/ Malayalam http://alaivani.com/?tabid=56&EntryID=192