10

Here is an extract from Wikipedia :

Samvatsara is a Sanskrit term for "year". In Hindu tradition, there are 60 Samvatsaras, each of which has a name. Once all 60 samvatsaras are over, the cycle starts over again. On occasion, one will be skipped, as the count is based on the zodiac position of Jupiter, whose period around the Sun is slightly less than 12 years (the full cycle of 60 covers five Jovian years).

Is there an astronomical representation for the cycle of 60 Samvatsaras ?

Remark: The zodiac position of Jupiter (Brihaspati) is not a sufficient explanation because five Jovian years correspond to 59 years and 113 days, so that there is a shift of 252 days for every cycle of 60 years.

  • Jupiter is Brihaspati, Saturn is Shani. Closing as unclear. – cheenbabes Jul 7 '14 at 15:02
  • @cheenbabes: you're right Jupiter is Brihaspati, but it's not me who put "Shani" (see the edits). Now you're free to improve the post as you want. – Sebastien Palcoux Jul 7 '14 at 15:19
9

Chaitramasi jagadbrahma sasarju prathamehaani Shukla paksha samagranthu thadaa suryodaye sathi Pravarthayaamaasa thatha kaalasya gananaamapi Grahantaaraan ruthoonmaasaan wathsaraanwathsaraadhipaan -Chaturvarga Chintamani

Lord Brahma created the Universe on the first day of Shukla Paksha of the Chaitra month. He created the planets, stars, seasons, years and Lords of years.

From their original union during the moment of Creation; the Sun and planets have moved endlessly forward from the same spot in the sky, each at their own speed. This region is the constellation of Aries, or mesha. This is the first constellation that the Sun enters after it crosses north of the Equator, the Spring Equinox. Chaitra marks the first month after the Sun enters the constellation of mesha. The lunar cycle has the same beginning, called Meshadi or the "start of Aries". Similiarly, the grahas (planets) started from mesha as well. Let's consider the slowest members of the planets, Jupiter & Saturn. Jupiter (Brihaspati) has a daily motion of 5 kalas (angular minutes), and takes ~ 12 years to return back in mesha. Saturn (Shani) has a daily motion of 2 kalas, and takes ~ 30 years to return. This way, it takes ~60 years for both Brihaspati & Shani to come together in mesha, which marks the first year of the samvatsara cycle.

The starting date was determined by Aryabhata, who backcalculated the positions of the planets to coincide at mesha at the beginning of Kali yuga, to 3102 BCE.

The choice of 3102 BCE had a special significance for Aryabhata. Midday at Ujjain on the equinoctial day 21 March CE 499 exactly corresponds to the beginning of the year 3600 of his Kaliyuga. Since the ardharatrikapaksa (midnight school) starts its Kaliyuga six hours before the Aryapaksa, Aryabhata artificially made the duration of the year slightly longer in the former case so that in both the schools the 3600th year starts at the same time. Significantly, CE 499 is the year of the composition of Aryabhatiya.

However, it is now known that planetary orbits are subject to various kinds of perturbations, and a theory depending on the orbital period as the sole parameter cannot give accurate results. According to modern numerical simulations, on 17/18 February 3102 BC the five geocentric planets were not aligned but spread over two neighboring zodiacal signs. This again underlines the inference that the significance of the date was hypothetical rather than real. In addition, the adhikmasa (leap month) methodology as introduced by Bhaskara II worked to shift the years from their original cycle.

In the Siddhanta Jyotisha, the Samvatsaras have been counted as 60 beginning from Vijaya and going down to Nandana. But Varahamihira in Brihat Samhita regarded the beginning of the Samvatsara cycle, not from Vijaya, but from the 35th Samvatsara of Prabhava. Since Varahamihira’s times it is this sequence which has been accepted.

For an astrological explanation, see here.

  • Unfortunately, every 60 years the relative position of Bṛhaspati (Jupiter) and Śani (Saturn) shifts too, so that this explanation is incomplete. For example, during the last Prabhava (from April 1987 to April 1988), Bṛhaspati crossed Meṣa (Aries), but Śani crossed Vṛścika (Scorpio) and Dhanus (Sagittarius), far from Meṣa ! – Sebastien Palcoux Jul 7 '14 at 12:54
  • It's not yet clear for me. The cycle of 60 years is an approximation for a return back of both Bṛhaspati and Śani. Now thanks to small shifts that add at every cycle, a given samvatsara year (for example Prabhava) does not correspond to a specific position of Bṛhaspati and Śani. That's why I don't really understand what this cycle means astronomically (or astrologically). – Sebastien Palcoux Jul 7 '14 at 15:37
  • 1
    It doesn't signify anything anymore. It did to the people who originally crafted it, for whom it marked the cycles of the yuga. Plus, the original Samvatsara in the Vedas and Puranas is 360 days, which is mirrored in Vedanga Jyotish and Surya Siddhantha (I think). The adhikmasa corrections try to match the sidereal 365 days. – Valarauko Jul 7 '14 at 15:47

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .