Panchang in Chahārbāgh, Alborz Province, Iran Wed 16 Jan 2030

Shiva’s Pradosh puja is done in pradosha, the 3 muhurtas after sunset. Trayodashi began at 16:33 on Wed 16 Jan, before that evening’s pradosha, and ended at 18:05 on Thu 17 Jan, partway into the next. The Nirnayasindhu takes the evening Trayodashi fills: Wed 16 Jan. 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: 132°–144° is the 12th, Shukla Dwadashi. A day takes the tithi in force at its sunrise, 07:15 here. Ekadashi ended at 14:30 Tue, before it. Dwadashi ends at 16:33, when the lead reaches 144°. The lead passed 0° at the new moon of 4 Jan, so the Moon is waxing: Shukla paksha.

The night of Tue 15 Jan ran from sunset 17:16 Tue to sunrise 07:15, 13 h 59 m. Cut into 15 muhurtas of 55 m, its 14th is Brahma Muhurta, the one before the last.

Daylight here, 07:15 to 17:17, splits into 8 choghadiyas of 1 h 15 m. Their names follow a fixed order that starts from the weekday, and each name is counted good, neutral or bad.

The night here, 17:17 to 07:15 Thu, splits into 8 choghadiyas of 1 h 44 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′. Rohini spans 40°00′–53°20′; the Moon entered its pada 4 at 50°. It leaves at 10:58, for Mrigashira.

Add the Sun's and the Moon's places among the stars: 271.8° + 51.5° = 323.3°. The sum, cut into 27 parts of 13°20′, gives the yoga: 320°00′–333°20′ is the 25th, Brahma. It ends at 01:38 Thu, then Indra.

A karana is half a tithi: 6° of the Moon's lead, so the first half of Dwadashi is Bava and the second Balava. Bava ended at 03:35, when the lead reached 138°; Balava runs until 16:33.

A Hindu day runs from one sunrise to the next, not midnight to midnight. This one runs 07:15 to 07:15 Thu, so the hours after midnight still belong to Budhawara.

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: Dhanu gives Pausha. The Sun enters Makara on 14 Jan, inside the month. The next new moon, 2 Feb, finds it in Makara and begins Magha.

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 Jan, with the Sun in Dhanu, began Pausha. This Shukla paksha reads Pausha in both counts.

A samvat year begins with Chaitra, the month whose new moon finds the Sun in Meena: 15 Mar 2029, 07:49 Thu. Since then the Sun has moved 301.2° round the stars. Vikram Samvat numbers that year 2086; Shaka Samvat numbers it 1951.