Panchang in Ipameri, Goiás, Brazil Fri 26 Apr 1957

Shiva’s Pradosh puja is done in pradosha, the 3 muhurtas after sunset. Trayodashi runs from 18:02 on Fri 26 Apr to 19:29 on Sat 27 Apr, touching pradosha on both evenings. The Nirnayasindhu takes the evening it holds more of: Fri 26 Apr. No text giving Pradosh Vrat’s time was found; pradosha is Tithika’s convention.

Pradosh Vrat: every date in Ipameri

The Moon gains on the Sun about 12° a day. Each 12° of lead is one tithi: 312°–324° is the 27th, Krishna Dwadashi. A day takes the tithi in force at its sunrise, 06:24 here. Ekadashi ended at 16:09 Thu, before it. Dwadashi ends at 18:02, when the lead reaches 324°. The lead passed 180° at the full moon of 14 Apr, so the Moon is waning: Krishna paksha.

The night of Thu 25 Apr ran from sunset 17:56 Thu to sunrise 06:24, 12 h 28 m. Cut into 15 muhurtas of 49 m, its 14th is Brahma Muhurta, the one before the last.

Daylight here, 06:24 to 17:56, splits into 8 choghadiyas of 1 h 26 m. Their names follow a fixed order that starts from the weekday, and each name is counted good, neutral or bad.

The night here, 17:56 to 06:24 Sat, splits into 8 choghadiyas of 1 h 33 m. Their names follow a fixed order that starts from the weekday, and each name is counted good, neutral or bad.

The fixed stars divide the Moon's path into 27 nakshatras of 13°20′, each in 4 padas of 3°20′. Purva Bhadrapada spans 320°00′–333°20′; the Moon entered its pada 4 at 330°. It leaves at 10:38, for Uttara Bhadrapada.

Add the Sun's and the Moon's places among the stars: 12.6° + 331.2° = 343.8°. The sum, cut into 27 parts of 13°20′, gives the yoga: 333°20′–346°40′ is the 26th, Indra. It ends at 11:39, then Vaidhriti.

A karana is half a tithi: 6° of the Moon's lead, so the first half of Dwadashi is Kaulava and the second Taitila. Kaulava ended at 05:09, when the lead reached 318°; Taitila runs until 18:02.

A Hindu day runs from one sunrise to the next, not midnight to midnight. This one runs 06:24 to 06:24 Sat, so the hours after midnight still belong to Shukrawara.

An amanta month runs from new moon to new moon and takes its name from the rashi the Sun is in at the new moon that begins it: Meena gives Chaitra. The Sun enters Mesha on 13 Apr, inside the month. The next new moon, 29 Apr, finds it in Mesha and begins Vaishakha.

A purnimanta month runs from full moon to full moon, so its waning half comes first. It shares its name with the amanta month that its second half falls in: the new moon of 29 Apr, with the Sun in Mesha, begins Vaishakha. Until then this Krishna paksha reads Vaishakha here, and Chaitra in the amanta count.

A samvat year begins with Chaitra, the month whose new moon finds the Sun in Meena: 31 Mar 1957, 06:18 Sun. Since then the Sun has moved 25.5° round the stars. Vikram Samvat numbers that year 2014; Shaka Samvat numbers it 1879.