CHAPTER 18
Calendar, Astrology,
and Astronomy
Michio Yano
Another title of this chapter could be jyotih.s ́a ̄stra, or “science of heavenly bodies.”
Sometimes mathematics (gan.itas ́a ̄stra) is regarded as a part ofjyotih.s ́a ̄stra, but an
independent chapter is given to mathematics in this book (see chapter 17). Thus,
what is touched on in this chapter is jyotih.s ́a ̄straminus mathematics proper. The
remainder can be expressed in the three words in the title of this chapter. Topics
are limited to those which would be useful for the students of Hinduism.
1 Veda ̄n.ga Calendar
Even taking into account the refined taste of Vedic poets who refrained from
describing natural phenomena in a direct manner, observational records of
heavenly phenomena are scarce in the Vedic sam.hita ̄literature. Of course the
poets were interested in the sky as nature, but they were less eager to engage in
mathematical formulation of the periodic changes in the starry heaven. So there
is nothing systematic in the sam.hita ̄texts that can be called mathematical
astronomy. What we find in them is the hymns to the Sun and the Moon, and
naks.atras. It is even doubtful whether they knew the five planets as such (grahas
in later texts), namely, as a special class of stars which are distinguished from
the fixed stars.
It was as one of the six auxiliary branches (an.ga) for the pursuit of Vedic
rituals that the earliest astronomical knowledge of ancient India was systemati-
cally described. This branch was called jyotis.aveda ̄n.ga. The word jyotis.acomes
fromjyotih., “light (in the sky), luminary.” The text of the jyotis.aveda ̄n.gasurvived
in two recensions: that of the R.gveda, which is older and ascribed to a Lagadha
belonging to the fifth century bc, and that of the Yajurveda, which belongs to
somewhat later period (Pingree 1981: 10). The two recensions, consisting of 36
and 44 verses respectively, have many verses in common.