Panchang in Ipameri, Goiás, Brazil Sun 29 Dec 2013

Shiva’s Pradosh puja is done in pradosha, the 3 muhurtas after sunset. Trayodashi runs from 19:28 on Sun 29 Dec to 16:29 on Mon 30 Dec, so only Sunday’s pradosha (19:50–22:00) falls within it. 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: 312°–324° is the 27th, Krishna Dwadashi. A day takes the tithi in force at its sunrise, 06:39 here. Ekadashi ended at 21:49 Sat, before it. Dwadashi ends at 19:28, when the lead reaches 324°. The lead passed 180° at the full moon of 17 Dec, so the Moon is waning: Krishna paksha.

The night of Sat 28 Dec ran from sunset 19:49 Sat to sunrise 06:39, 10 h 50 m. Cut into 15 muhurtas of 43 m, its 14th is Brahma Muhurta, the one before the last.

Daylight here, 06:39 to 19:50, splits into 8 choghadiyas of 1 h 38 m. Their names follow a fixed order that starts from the weekday, and each name is counted good, neutral or bad.

The night here, 19:50 to 06:40 Mon, splits into 8 choghadiyas of 1 h 21 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′. Vishakha spans 200°00′–213°20′; the Moon entered its pada 4 at 210°. It leaves at 11:16, for Anuradha.

Add the Sun's and the Moon's places among the stars: 253.7° + 210.6° = 464.3°, one full turn and 104.3°. Past the turn, cut into 27 parts of 13°20′, it gives the yoga: 93°20′–106°40′ is the 8th, Dhriti. It ends at 10:20, then Shula.

A karana is half a tithi: 6° of the Moon's lead, so the first half of Dwadashi is Kaulava and the second Taitila. Kaulava runs until 08:44, when the lead reaches 318°; Taitila until 19:28.

A Hindu day runs from one sunrise to the next, not midnight to midnight. This one runs 06:39 to 06:40 Mon, so the hours after midnight still belong to Raviwara.

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: Vrishchika gives Margashirsha. The Sun enters Dhanu on 15 Dec, inside the month. The next new moon, 1 Jan, finds it in Dhanu and begins Pausha.

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 1 Jan, with the Sun in Dhanu, begins Pausha. Until then this Krishna paksha reads Pausha here, and Margashirsha in the amanta count.

A samvat year begins with Chaitra, the month whose new moon finds the Sun in Meena: 10 Apr 2013, 06:35 Wed. Since then the Sun has moved 257.1° round the stars. Vikram Samvat numbers that year 2070; Shaka Samvat numbers it 1935.