Panchang in Sevan, Gegharkunik, Armenia Tue 27 May 1980

Shiva’s Pradosh puja is done in pradosha, the 3 muhurtas after sunset. Trayodashi runs from 21:50 on Mon 26 May to 23:31 on Tue 27 May, touching pradosha on both evenings. The Nirnayasindhu takes the evening it holds more of: Tue 27 May. 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, 05:34 here. Dwadashi ended at 21:50 Mon, before it. Trayodashi ends at 23:31, when the lead reaches 156°. The lead passed 0° at the new moon of 14 May, so the Moon is waxing: Shukla paksha.

The night of Mon 26 May ran from sunset 20:19 Mon to sunrise 05:34, 9 h 15 m. Cut into 15 muhurtas of 37 m, its 14th is Brahma Muhurta, the one before the last.

Daylight here, 05:34 to 20:20, splits into 8 choghadiyas of 1 h 50 m. Their names follow a fixed order that starts from the weekday, and each name is counted good, neutral or bad.

The night here, 20:20 to 05:33 Wed, splits into 8 choghadiyas of 1 h 9 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′. Swati spans 186°40′–200°00′; the Moon entered its pada 1 at 186°40′. It leaves at 01:22 Wed, for Vishakha.

Add the Sun's and the Moon's places among the stars: 42.3° + 189.9° = 232.2°. The sum, cut into 27 parts of 13°20′, gives the yoga: 226°40′–240°00′ is the 18th, Variyana. It ends at 19:41, then Parigha.

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 10:44, when the lead reaches 150°; Taitila until 23:31.

A Hindu day runs from one sunrise to the next, not midnight to midnight. This one runs 05:34 to 05:33 Wed, so the hours after midnight still belong to Mangalawara.

A month normally holds one sankranti, the Sun's entry into a new rashi. From 14 May 16:00 Wed to 13 Jun 00:38 Fri the Sun stayed in Vrishabha, entering Mithuna at 14 Jun 16:25 Sat, after the new moon. A month with no sankranti is Adhika Jyeshtha, before Jyeshtha 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 14 May, with the Sun in Vrishabha, began Jyeshtha (Adhik). This Shukla paksha reads Jyeshtha (Adhik) in both counts.

A samvat year begins with Chaitra, the month whose new moon finds the Sun in Meena: 16 Mar 1980, 22:55 Sun. Since then the Sun has moved 69.5° round the stars. Vikram Samvat numbers that year 2037; Shaka Samvat numbers it 1902.