Panchang in Sevan, Gegharkunik, Armenia Wed 28 Jul 1920

Shiva’s Pradosh puja is done in pradosha, the 3 muhurtas after sunset. Trayodashi runs from 19:54 on Tue 27 Jul to 22:17 on Wed 28 Jul, touching pradosha on both evenings. The Nirnayasindhu takes the evening it holds more of: Wed 28 Jul. No text giving Pradosh Vrat’s time was found; pradosha is Tithika’s convention.

Pradosh Vrat: every date in Sevan

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, 04:52 here. Dwadashi ended at 19:56 Tue, before it. Trayodashi ends at 22:19, when the lead reaches 156°. The lead passed 0° at the new moon of 15 Jul, so the Moon is waxing: Shukla paksha.

The night of Tue 27 Jul ran from sunset 19:20 Tue to sunrise 04:52, 9 h 32 m. Cut into 15 muhurtas of 38 m, its 14th is Brahma Muhurta, the one before the last.

Daylight here, 04:52 to 19:19, splits into 8 choghadiyas of 1 h 48 m. Their names follow a fixed order that starts from the weekday, and each name is counted good, neutral or bad.

The night here, 19:19 to 04:53 Thu, splits into 8 choghadiyas of 1 h 11 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′. Mula spans 240°00′–253°20′; the Moon entered its pada 3 at 246°40′. It leaves at 11:40, for Purva Ashadha.

Add the Sun's and the Moon's places among the stars: 101.9° + 249.9° = 351.8°. The sum, cut into 27 parts of 13°20′, gives the yoga: 346°40′–360°00′ is the 27th, Vaidhriti. It ends at 20:02, then Vishkambha.

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 09:09, when the lead reaches 150°; Taitila until 22:19.

A Hindu day runs from one sunrise to the next, not midnight to midnight. This one runs 04:52 to 04:53 Thu, so the hours after midnight still belong to Budhawara.

A month normally holds one sankranti, the Sun's entry into a new rashi. From 15 Jul 23:24 Thu to 14 Aug 06:43 Sat the Sun stayed in Karka, entering Simha at 16 Aug 01:42 Mon, after the new moon. A month with no sankranti is Adhika Shravana, before Shravana itself.

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 15 Jul, with the Sun in Karka, began Shravana (Adhik). This Shukla paksha reads Shravana (Adhik) in both counts.

A samvat year begins with Chaitra, the month whose new moon finds the Sun in Meena: 20 Mar 1920, 13:55 Sat. Since then the Sun has moved 125.1° round the stars. Vikram Samvat numbers that year 1977; Shaka Samvat numbers it 1842.