The upanayana, the sacred thread ceremony also called janeu or vratabandha, has one of the longest sets of rules in the Muhurta Chintamani. They sit in its Samskara prakarana (chapter 5), verses 39 to 57, with a few general rules from the first chapter. This page sets out the ones that can be checked from the sky and lists the days in New Delhi that pass all of them, with the hours of each day in which they do.
How it works
The verse numbers below are those of the edition with the Hindi commentary of Mahidhara Sharma (Venkateshwar Press), and where a verse needs explaining we follow that commentary.
Nakshatra (verse 40). The Moon must be in one of these: the quick group (Ashwini, Pushya, Hasta), the fixed group (Rohini and the three Uttaras), Ashlesha, the movable group (Punarvasu, Swati, Shravana, Dhanishta, Shatabhisha), Moola, the gentle group (Mrigashira, Chitra, Anuradha, Revati), the three Purvas and Ardra.
Weekday and tithi (verses 40 and 48). Sunday, Monday, Wednesday, Thursday or Friday; verse 48 rules out Saturday. The tithi must be Dwitiya, Tritiya, Panchami, Dashami, Ekadashi or Dwadashi of the bright half, or Dwitiya, Tritiya or Panchami of the dark half, because the dark half is allowed only in its first third.
Season (verse 26). Not in the southward half of the year: the Sun must be in Makara, Kumbha, Meena, Mesha, Vrishabha or Mithuna, counted in the sidereal zodiac.
Jupiter, Venus and the leaped month (chapter 1, verse 47). The sacred thread is on the list of acts not begun while Jupiter or Venus is combust (asta) or in a leaped (adhika) month. We take asta as Venus within 10 degrees of the Sun moving direct or 8 degrees moving retrograde, and Jupiter within 11 degrees, the Surya Siddhanta figures used on every muhurat page here.
Infancy and old age of Jupiter and Venus. The same verse, and verse 26 of this chapter, also name the days of infancy and old age (bala and vriddha), just after Jupiter or Venus rises from asta and just before it sets. Verses 27 and 28 count those days in several ways: as Mahidhara Sharma gives them, Venus is young for 3 days after rising in the east and 10 after rising in the west, and old for 15 days before setting in the east and 5 before setting in the west, and Jupiter for 15 days each way; other views give 10 days or 7, and only 3 in an emergency. The common panchang practice leaves out the 3 days before the planet sets and the 3 days after it rises, and we follow it, so those days are left out as well as the asta itself. If your family counts more days, your astrologer can strike them.
Sun and Jupiter in one sign, and a short paksha (chapter 1, verse 48, not applied). Mahidhara Sharma reads this verse as holding back the same acts as asta while the Sun and Jupiter are in the same sign (guru-aditya), and in a paksha that holds only thirteen sunrises because tithis are lost in it (vishvaghasra). Readings differ: the common panchang practice uses neither bar, and we follow it, so no day is left out for either.
Hours (verses 40 and 48). Not in the afternoon and not at night. Mahidhara Sharma explains the afternoon (aparahna) as the last third of the daytime, so a window runs at most from sunrise to the end of the second third of the day.
Days left out (verses 54 and 55, and chapter 1, verse 57). The day of a Sankranti; four named tithis of the bright half (Ashadha Dashami, Jyeshtha Dwitiya, Pausha Ekadashi and Magha Dwadashi); the manvadi and yugadi tithis, which include Vaishakha Shukla Tritiya, Akshaya Tritiya; and a pradosha day, when the day’s Tritiya, Shashthi or Dwadashi ends before a quarter, three eighths or half of the night has passed.
From the general rule of chapter 1, verse 34, as on every page here: no Vishti karana and no Vyatipata or Vaidhriti yoga. That verse and the next list more, which are named under What it does not do.
Reading the result
Each listed day has at least one window of five minutes or more in which every condition holds, and the window is shown with the nakshatra and tithi in force. Because the hour rule closes the afternoon and the night, every window here falls between sunrise and the early afternoon. The months with no days are the southward half of the year and the periods when Jupiter or Venus is combust; that is the rule at work, not a gap in the table. For another city, the muhurat finder runs the same rule with that place’s sunrise.
Where traditions differ
Some families hold the sacred thread on Akshaya Tritiya or Vasant Panchami by custom, as days that need no further check. The text lists Akshaya Tritiya among the yugadi days on which study does not begin, so this method leaves it out; Vasant Panchami, a Shukla Panchami, passes the tithi rule and stands or falls by the other conditions. Families of the four Vedas also follow different nakshatra lists (verse 57 gives one for each Veda), and many priests weigh the boy’s age and Jupiter’s position for him above the rest. We apply the general list of verse 40 for everyone and say so. Verse 48 of the first chapter also holds these acts back while Jupiter is in Simha or Makara, and verses 49 to 52 then limit or lift that part by region and by where in the sign Jupiter stands; some teachers, Mahidhara Sharma notes, also keep them back for 28 days when Jupiter is retrograde or moving fast (vakra and atichara). Readings differ; the common panchang practice holds these acts back for neither, and we follow it, so this page does not apply those parts.
What it does not do
It does not choose the boy’s year: verse 39 names the eighth year from conception or birth for a Brahmin boy, with other ages for other families, and that is the family’s to decide. It does not check Jupiter’s strength from the boy’s own Moon sign (verses 46 and 47), the lagna at the hour (verses 41 and 42), thunder at dawn or the other omens of verse 48, a comet in the sky (verse 26), or your family’s own branch of the Veda. Your family priest or astrologer settles those, and a day missing here is not a bad day: it only fails one of the conditions above. Chapter 1, verses 34 and 35 also name things every auspicious act avoids that this page does not check: the person’s own birth nakshatra, month and tithi and a parent’s shraddha day; a day touched by three tithis or a tithi that touches three days (tithi kshaya and vriddhi); kulika, the half-prahara and mahapata; and the opening part of the yogas Vishkambha, Vajra, Shoola, Ganda, Atiganda and Vyaghata and the first half of Parigha. An almanac that applies them may list fewer days. The lost (kshaya) month that verse 34 also names, a lunar month in which the Sun enters two signs between one new moon and the next (as Mahidhara Sharma explains it), is left out; from 1952 to 2073 there are two, beginning with the new moons of 16 November 1963 and 14 January 1983, Indian time.
For the ceremony itself, read the page on upanayana as a samskara. The tarabala and chandrabala calculators check a day against the boy’s own birth star and Moon, and the other events are on the muhurat hub.