TheModengqie Jing, one of the Chinese translations of the S ́a ̄rdu ̄ lakarn.a ̄vada ̄na,
adds in this context Ra ̄hu and comets (or a comet) to the seven luminaries and
regards “nine” grahasas making one group. What is more interesting is that the
week-day order of seven grahasis attested in a passage of this Chinese transla-
tion (Taisho Daizôkyô, vol. 21: 410). It is quite puzzling to find the week-day
order here, because the Chinese translation is said to have been made in the early
third century ad. This was the time when the notion of the week-day was just
introduced into India. In order to settle this puzzle we must hypothesize either
(1) that the Chinese translators got some new information directly from the west
or (2) that this passage was inserted in a somewhat later period.
Week-day order of grahas It was only after the transmission of Hellenistic astrol-
ogy that the order of planets in India was fixed in that of the seven-day week.
This order is the outcome of the combination of the Greek cosmological idea of
concentric spheres and the Egyptian belief of the planetary gods presiding over
the 24 hours (wramentioned above). In order to get the present order of week-
day, the concentric spheres must be arranged in the order of Saturn, Jupiter,
Mars, the Sun, Venus, Mercury, and the Moon. This order was known sometime
in the second century bc. But the evidence of the earliest use of the week-day
belongs to a considerably later period.
The first evidence of the introduction of Greek astrology in India is the
Yavanaja ̄taka. The text was translated into Sanskrit prose in ad149/150 and it
was versified in ad269/270 by a Sphujidhvaja. Only the verse version is extant
(Pingree 1978). Sphujidhvaja’s version enumerates seven planets on many
occasions, but it is only towards the end of the work (chapter 77) that the week-
day order is attestable. This order does not seem to have been widely spread in
that period in India. Neither Ra ̄hu nor Ketu appears in this text. About a quarter
century later, however, Mı ̄nara ̄ja in his Vr.ddhayavanaja ̄taka(about ad300–25)
describes planets in the week-day order, together with Ra ̄hu, although he does
not mention Ketu (Pingree 1976). Vara ̄hamihira (mid-sixth century) does not
regard Ketu as the tail of Ra ̄hu but as comets.
The oldest Indian inscription which gives a date with a week-day is that
of Thursday, 21 July, ad484 (Fleet 1877: 80–4). The first astronomical text
which defines the week-day is the A ̄ryabhat. ̄yaı of A ̄ryabhat.a (born ad476). His
definition is:
These seven Lords ofhora ̄beginning with Saturn are (more and more) speedy in
this order (of concentric spheres). Every fourth by the order of swiftness is the Lord
of the day (which begins) with the sunrise. (ABh. 3.16)
What we can safely say is, therefore, that the week-day and the order of the days
of the week gradually became known to Indian people at the end of the third
century and it became wide spread about a century later.
calendar, astrology, and astronomy 383