Panchang in Progress, Amur Oblast, Russia Tue 16 Aug 2016

Shiva’s Pradosh puja is done in pradosha, the 3 muhurtas after sunset. Trayodashi runs from 21:19 on Mon 15 Aug to 20:56 on Tue 16 Aug, touching pradosha on both evenings. The Nirnayasindhu takes the evening it holds more of: Tue 16 Aug. No text giving Pradosh Vrat’s time was found; pradosha is Tithika’s convention.

Pradosh Vrat: every date in Progress

The Moon gains on the Sun about 12° a day. Each 12° of lead is one tithi: 144°–156° is the 13th, Shukla Trayodashi. A day takes the tithi in force at its sunrise, 05:13 here. Dwadashi ended at 21:19 Mon, before it. Trayodashi ends at 20:56, when the lead reaches 156°. The lead passed 0° at the new moon of 3 Aug, so the Moon is waxing: Shukla paksha.

The night of Mon 15 Aug ran from sunset 19:38 Mon to sunrise 05:13, 9 h 35 m. Cut into 15 muhurtas of 38 m, its 14th is Brahma Muhurta, the one before the last.

Daylight here, 05:13 to 19:36, splits into 8 choghadiyas of 1 h 47 m. Their names follow a fixed order that starts from the weekday, and each name is counted good, neutral or bad.

The night here, 19:36 to 05:14 Wed, splits into 8 choghadiyas of 1 h 12 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′. Uttara Ashadha spans 266°40′–280°00′; the Moon entered its pada 1 at 266°40′. It leaves at 04:12 Wed, for Shravana.

Add the Sun's and the Moon's places among the stars: 119.3° + 267.3° = 386.6°, one full turn and 26.6°. Past the turn, cut into 27 parts of 13°20′, it gives the yoga: 13°20′–26°40′ is the 2nd, Priti. It ends at 05:17, then Ayushmana.

A karana is half a tithi: 6° of the Moon's lead, so the first half of Trayodashi is Kaulava and the second Taitila. Kaulava runs until 09:12, when the lead reaches 150°; Taitila until 20:56.

A Hindu day runs from one sunrise to the next, not midnight to midnight. This one runs 05:13 to 05:14 Wed, so the hours after midnight still belong to Mangalawara.

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: Karka gives Shravana. The Sun enters Simha on 16 Aug, inside the month. The next new moon, 1 Sep, finds it in Simha and begins Bhadrapada.

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 3 Aug, with the Sun in Karka, began Shravana. This Shukla paksha reads Shravana in both counts.

A samvat year begins with Chaitra, the month whose new moon finds the Sun in Meena: 7 Apr 2016, 20:23 Thu. Since then the Sun has moved 125.3° round the stars. Vikram Samvat numbers that year 2073; Shaka Samvat numbers it 1938.