Panchang in Ipameri, Goiás, Brazil Tue 27 Apr 1915

Shiva’s Pradosh puja is done in pradosha, the 3 muhurtas after sunset. Trayodashi runs from 21:13 on Mon 26 Apr to 18:23 on Tue 27 Apr, so it touches only Tuesday’s pradosha (17:56–20:25). No text giving Pradosh Vrat’s time was found; pradosha is Tithika’s convention.

Pradosh Vrat: every date in Ipameri

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, 06:24 here. Dwadashi ended at 21:13 Mon, before it. Trayodashi ends at 18:23, when the lead reaches 156°. The lead passed 0° at the new moon of 14 Apr, so the Moon is waxing: Shukla paksha.

The night of Mon 26 Apr ran from sunset 17:56 Mon to sunrise 06:24, 12 h 28 m. Cut into 15 muhurtas of 49 m, its 14th is Brahma Muhurta, the one before the last.

Daylight here, 06:24 to 17:56, splits into 8 choghadiyas of 1 h 26 m. Their names follow a fixed order that starts from the weekday, and each name is counted good, neutral or bad.

The night here, 17:56 to 06:24 Wed, splits into 8 choghadiyas of 1 h 33 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′. Hasta spans 160°00′–173°20′; the Moon entered its pada 1 at 160°. It leaves at 00:01 Wed, for Chitra.

Add the Sun's and the Moon's places among the stars: 13.4° + 162.5° = 175.9°. The sum, cut into 27 parts of 13°20′, gives the yoga: 173°20′–186°40′ is the 14th, Harshana. It ends at 22:53, then Vajra.

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 07:52, when the lead reaches 150°; Taitila until 18:23.

A Hindu day runs from one sunrise to the next, not midnight to midnight. This one runs 06:24 to 06:24 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 Apr 08:35 Wed to 14 May 00:30 Fri the Sun stayed in Mesha, entering Vrishabha at 14 May 10:42 Fri, after the new moon. A month with no sankranti is Adhika Vaishakha, before Vaishakha 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 Apr, with the Sun in Mesha, began Vaishakha (Adhik). This Shukla paksha reads Vaishakha (Adhik) in both counts.

A samvat year begins with Chaitra, the month whose new moon finds the Sun in Meena: 15 Mar 1915, 16:41 Mon. Since then the Sun has moved 41.9° round the stars. Vikram Samvat numbers that year 1972; Shaka Samvat numbers it 1837.