Panchang in Ipameri, Goiás, Brazil Sun 13 Dec 2009

Shiva’s Pradosh puja is done in pradosha, the 3 muhurtas after sunset. Trayodashi runs from 07:06 on Sun 13 Dec to 07:37 on Mon 14 Dec, so only Sunday’s pradosha (19:42–21:52) 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, 06:31 here. Ekadashi ended at 07:02 Sat, before it. Dwadashi ends at 07:06, when the lead reaches 324°. The lead passed 180° at the full moon of 2 Dec, so the Moon is waning: Krishna paksha.

The night of Sat 12 Dec ran from sunset 19:41 Sat to sunrise 06:31, 10 h 50 m. Cut into 15 muhurtas of 43 m, its 14th is Brahma Muhurta, the one before the last.

Daylight here, 06:31 to 19:42, 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, 19:42 to 06:32 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 1 at 200°. It leaves at 05:21 Mon, for Anuradha.

Add the Sun's and the Moon's places among the stars: 237.5° + 201.2° = 438.7°, one full turn and 78.7°. Past the turn, cut into 27 parts of 13°20′, it gives the yoga: 66°40′–80°00′ is the 6th, Atiganda. It ends at 08:52, then Sukarma.

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 ended at 19:00 Sat, when the lead reached 318°; Taitila runs until 07:06.

A Hindu day runs from one sunrise to the next, not midnight to midnight. This one runs 06:31 to 06:32 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, 16 Dec, 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 16 Dec, 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: 26 Mar 2009, 13:05 Thu. Since then the Sun has moved 255.4° round the stars. Vikram Samvat numbers that year 2066; Shaka Samvat numbers it 1931.