Panchang in Davinópolis, Maranhão, Brazil Fri 19 Dec 2014

Shiva’s Pradosh puja is done in pradosha, the 3 muhurtas after sunset. Trayodashi runs from 03:16 on Fri 19 Dec to 02:22 on Sat 20 Dec, so only Friday’s pradosha (18:20–20:38) falls within it. No text giving Pradosh Vrat’s time was found; pradosha is Tithika’s convention.

Pradosh Vrat: every date in Davinópolis

The Moon gains on the Sun about 12° a day. Each 12° of lead is one tithi: 324°–336° is the 28th, Krishna Trayodashi. A day takes the tithi in force at its sunrise, 05:53 here. Dwadashi ended at 03:16, before it. Trayodashi ends at 02:22 Sat, when the lead reaches 336°. The lead passed 180° at the full moon of 6 Dec, so the Moon is waning: Krishna paksha.

A day takes the tithi in force at its sunrise.

New Delhi · IST

Sunrise here, 07:08, came before Dwadashi ended at 11:46: this day reads Dwadashi.

Davinópolis · UTC−3

Sunrise here, 05:53, came after Dwadashi ended at 03:16: this day reads Trayodashi.

The night of Thu 18 Dec ran from sunset 18:19 Thu to sunrise 05:53, 11 h 34 m. Cut into 15 muhurtas of 46 m, its 14th is Brahma Muhurta, the one before the last.

Daylight here, 05:53 to 18:20, 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 night here, 18:20 to 05:53 Sat, 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 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 3 at 206°40′. It leaves at 14:18, for Anuradha.

Add the Sun's and the Moon's places among the stars: 243.3° + 208.6° = 451.9°, one full turn and 91.9°. Past the turn, cut into 27 parts of 13°20′, it gives the yoga: 80°00′–93°20′ is the 7th, Sukarma. It ends at 08:14, then Dhriti.

A karana is half a tithi: 6° of the Moon's lead, so the first half of Trayodashi is Garaja and the second Vanija. Garaja runs until 14:54, when the lead reaches 330°; Vanija until 02:22 Sat.

A Hindu day runs from one sunrise to the next, not midnight to midnight. This one runs 05:53 to 05:53 Sat, so the hours after midnight still belong to Shukrawara.

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 16 Dec, inside the month. The next new moon, 21 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 21 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: 30 Mar 2014, 15:44 Sun. Since then the Sun has moved 257.4° round the stars. Vikram Samvat numbers that year 2071; Shaka Samvat numbers it 1936.