- Born
- 12 January 1863, 6:31 AM
- Clock
- Local mean time of Calcutta (UTC+5:53:28)
- Place
- Datta family house, 3 Gourmohan Mukherjee Street, Simla (Simulia), Calcutta, Bengal Presidency, British India (Kolkata, India)
- Coordinates
- 22.5863, 88.3674
- Birth time
- from the person's own or the family's account
- How the time stands
- The time is the family's own: his younger brother Bhupendranath Datta prints 6.31.33 a.m. and says in a footnote that it is taken from the original horoscope. It is A, not AA, because the horoscope itself was not seen, and other accounts said to rest on the same horoscope put the birth up to about 11 minutes later.
- About the clock
- India had no standard time in 1863 and Calcutta kept its own mean solar time, so the offset is the house's longitude times 4 minutes; zoneinfo's Asia/Kolkata gives Howrah Mean Time (UTC+5:53:20) for 1863, the same local clock to within 8 seconds.
Other times printed elsewhere
- 06:33:33 · The Life of Swami Vivekananda by His Eastern and Western Disciples, fifth edition (1979) onward (vol. 1, p. 11 in the 1989 sixth edition): '33 minutes and 33 seconds after six'. No source is named; it probably comes from the same horoscope as Bhupendranath Datta's 6.31.33, with one of the two misprinted.
- 06:43 · Implied by Rajendranath Ghosh's letter in Pramathanath Basu's Swami Vivekananda, vol. 2, appendix: he says his 6:49 is six minutes later than the time in the horoscope copied from the original by Abinash Chandra Gangopadhyay and checked with Vivekananda's mother. The copy's own time is not printed; 06:43 is our subtraction, and it puts the sidereal ascendant at the end of Sagittarius, as Ghosh says the old horoscope had it.
- 06:37 · The Life of Swami Vivekananda by His Eastern and Western Disciples, revised second edition (1933) to the 1960s, and Swami Gambhirananda's Yuganayak Vivekananda (1966): 'six minutes before the sunrise'. The clock time is our conversion, using the computed visible sunrise at 06:42:39 local mean time; with the almanac sunrise implied by Basu's horoscope (about 06:48) it would be about 06:42.
- 06:49 · Rajendranath Ghosh's rectification, printed in Pramathanath Basu's Swami Vivekananda, vol. 2, appendix 'Koshthi-bichar' (p. 987): the horoscope time moved six minutes later so that Capricorn (Makara) rises sidereally, to fit the events of his life; repeated by Swami Nikhilananda (1953) as 'a few minutes after sunrise'.
