Panchang in Ipameri, Goiás, Brazil Sat 12 Nov 2016

Shiva’s Pradosh puja is done in pradosha, the 3 muhurtas after sunset. Trayodashi runs from 22:53 on Fri 11 Nov to 19:31 on Sat 12 Nov, so it touches only Saturday’s pradosha (19:24–21:37). 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, 06:29 here. Dwadashi ended at 22:53 Fri, before it. Trayodashi ends at 19:31, when the lead reaches 156°. The lead passed 0° at the new moon of 30 Oct, so the Moon is waxing: Shukla paksha.

The night of Fri 11 Nov ran from sunset 19:24 Fri to sunrise 06:29, 11 h 5 m. Cut into 15 muhurtas of 44 m, its 14th is Brahma Muhurta, the one before the last.

Daylight here, 06:29 to 19:24, splits into 8 choghadiyas of 1 h 36 m. Their names follow a fixed order that starts from the weekday, and each name is counted good, neutral or bad.

The night here, 19:24 to 06:29 Sun, splits into 8 choghadiyas of 1 h 23 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′. Revati spans 346°40′–360°00′; the Moon entered its pada 3 at 353°20′. It leaves at 15:00, for Ashwini.

Add the Sun's and the Moon's places among the stars: 206.3° + 354.7° = 561°, one full turn and 201°. Past the turn, cut into 27 parts of 13°20′, it gives the yoga: 200°00′–213°20′ is the 16th, Siddhi. It ends at 00:57 Sun, then Vyatipata.

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 09:16, when the lead reaches 150°; Taitila until 19:31.

A Hindu day runs from one sunrise to the next, not midnight to midnight. This one runs 06:29 to 06:29 Sun, so the hours after midnight still belong to Shaniwara.

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: Tula gives Kartika. The Sun enters Vrishchika on 15 Nov, inside the month. The next new moon, 29 Nov, finds it in Vrishchika and begins Margashirsha.

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 30 Oct, with the Sun in Tula, began Kartika. This Shukla paksha reads Kartika in both counts.

A samvat year begins with Chaitra, the month whose new moon finds the Sun in Meena: 7 Apr 2016, 08:23 Thu. Since then the Sun has moved 212.3° round the stars. Vikram Samvat numbers that year 2073; Shaka Samvat numbers it 1938.