पञ्चसिद्धान्तिका (आचार्य वराहमिहिर - सूर्य, रोमक, पौलिश, वासिष्ठ एवं पितामह सिद्धान्त)

64 PAÑCASIDDHĀNTIKĀ III.24
[षडशीतिपुण्यकालः]
मेषतुलादौ विषुवं षडशीतिमुखं तुलादिभागेषु ।
षडशीतिमुखेषु रवेः पितृदिवसा ये (ऽव) शेषाः स्युः ॥ २३ ॥
षडशीतिमुखं कन्याचतुर्दशेऽष्टादशे च मिथुनस्य ।
मीनस्य द्वाविंशे षड्विंशे कार्मुकस्यांशे ॥२४ ॥
Ṣaḍaśīti-puṇyakāla
23-24. At the first point of Meṣa (Aries) and Tulā (Libra) are the spring and
autumnal equinoxes (and the sacred days thereof are when the Sun is there.)
The commencements of the sacred days called Ṣaḍaśītis are at periods of 86
solar degrees commencing with Tulā-zero point. The days in the solar months
after the respective commencement of the Ṣaḍaśītis are sacred as connected
with the manes. The commencement of the Ṣaḍaśītis are after 14 degrees of
Kanyā, (Virgo), after 18 degrees of Mithuna (Gemini), after 22 degrees of
Mīna, (Pisces) and after 26 degrees of Dhanus (Sagittarius).
The main purpose of the author in giving the equinoxes here is to indicate the sacred days con-
nected with them as can be gathered from the context. The equinoxes, i.e. the points of intersection
between the ecliptic and the celestial equator, though moving westward slowly along the ecliptic,
(this is the precession of the equinoxes), were at the first points of Meṣa and Tulā only at the period
of the author. At the present day the equinoxes have moved far into Uttara-Bhādrapada and
Uttara-Phalgunī, but the sacred days are still observed with the Sun entering Meṣa and Tulā by
blind routine.
The time taken by the Sun to move one degree is a ‘solar day’ according to Hindu astronomers.
(We have put it within inverted commas, because in English it means the ordinary day caused by
the Sun and therefore quite different). So in a solar year there are 360 ‘solar days’, and in each solar
month 30 ‘solar days’. As for counting from zero-Tulā, this is enjoined by the Dharma-śāstras. The
commencements of the Ṣaḍaśītimukha-s are, 1 × 86° = 86°, 2 × 86° = 172°, 3 × 86° = 258° and 4 ×
86° = 344°. from zero-Tulā, i.e. from rā. 6-0-0. Therefore they are rā. 6 + 86°, rā. 6 + 172°, rā. 6

• 258° and rā. 6 + 344°, and these are, respectively, 26 degrees of Sagittarius, 22 degrees of Pisces,
  18 degrees of Gemini and 14 degrees of Virgo. These sacred days are not observed in these days
  and it would be interesting to know when and how they went out of vogue. When the Sun enters
  Sagittarius, Pisces, Gemini and Virgo, we observe the sacred day, calling it Ṣaḍaśīti; and in the place
  of the last sixteen ‘solar days’ of Virgo, (these seem to have secured importance at the time of Sūrya
  Siddhānta) the dark fortnight of Bhādrapada is dedicated to the Manes, with the name of Mahālaya-
  pakṣa. The dark fortnight of Āśvina also is observed as a secondary Mahālaya-pakṣa and it is the
  belief that the Manes are sent back to their world on Naraka-Caturdaśī. Now, what is the speciality
  about 86 solar days, it may be asked. This period is three synodic months less one day. It may be
  23a. A. मेखतुलादौ A.विषुव; B.1.2. C.D.विषुवत्; B3.दिषु
  b. A. षडसीति d. A.B.विशेषा स्युः
  c. A.B.दिवसाद्ये 24b. A. °ष्टादर्शे