Panchang in Chahārbāgh, Alborz Province, Iran Thu 2 Apr 1981

Shiva’s Pradosh puja is done in pradosha, the 3 muhurtas after sunset. Trayodashi runs from 09:02 on Thu 2 Apr to 06:28 on Fri 3 Apr, so only Thursday’s pradosha (18:29–20:45) falls within it. No text giving Pradosh Vrat’s time was found; pradosha is Tithika’s convention.

Pradosh Vrat: every date in Chahārbāgh

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, 05:52 here. Ekadashi ended at 10:55 Wed, before it. Dwadashi ends at 09:02, when the lead reaches 324°. The lead passed 180° at the full moon of 20 Mar, so the Moon is waning: Krishna paksha.

The night of Wed 1 Apr ran from sunset 18:28 Wed to sunrise 05:52, 11 h 24 m. Cut into 15 muhurtas of 45 m, its 14th is Brahma Muhurta, the one before the last.

Daylight here, 05:52 to 18:29, splits into 8 choghadiyas of 1 h 34 m. Their names follow a fixed order that starts from the weekday, and each name is counted good, neutral or bad.

The night here, 18:29 to 05:50 Fri, splits into 8 choghadiyas of 1 h 25 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′. Shatabhisha spans 306°40′–320°00′; the Moon entered its pada 2 at 310°. It leaves at 21:05, for Purva Bhadrapada.

Add the Sun's and the Moon's places among the stars: 348.7° + 310.9° = 659.6°, one full turn and 299.6°. Past the turn, cut into 27 parts of 13°20′, it gives the yoga: 293°20′–306°40′ is the 23rd, Shubha. It ends at 17:00, then Shukla.

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 22:04 Wed, when the lead reached 318°; Taitila runs until 09:02.

A Hindu day runs from one sunrise to the next, not midnight to midnight. This one runs 05:52 to 05:50 Fri, so the hours after midnight still belong to Guruwara.

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: Kumbha gives Phalguna. The Sun enters Meena on 14 Mar, inside the month. The next new moon, 4 Apr, finds it in Meena and begins Chaitra.

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 4 Apr, with the Sun in Meena, begins Chaitra. Until then this Krishna paksha reads Chaitra here, and Phalguna in the amanta count.

A samvat year begins with Chaitra, the month whose new moon finds the Sun in Meena: 16 Mar 1980, 22:25 Sun. Since then the Sun has moved 375.9° round the stars. Vikram Samvat numbers that year 2037; Shaka Samvat numbers it 1902.