Panchang in Ipameri, Goiás, Brazil Sat 30 May 2015

Shiva’s Pradosh puja is done in pradosha, the 3 muhurtas after sunset. Trayodashi runs from 12:13 on Sat 30 May to 13:12 on Sun 31 May, so only Saturday’s pradosha (17:44–20:19) 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: 132°–144° is the 12th, Shukla Dwadashi. A day takes the tithi in force at its sunrise, 06:35 here. Ekadashi ended at 10:37 Fri, before it. Dwadashi ends at 12:13, when the lead reaches 144°. The lead passed 0° at the new moon of 18 May, so the Moon is waxing: Shukla paksha.

The night of Fri 29 May ran from sunset 17:44 Fri to sunrise 06:35, 12 h 51 m. Cut into 15 muhurtas of 51 m, its 14th is Brahma Muhurta, the one before the last.

Daylight here, 06:35 to 17:44, 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 night here, 17:44 to 06:36 Sun, 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 fixed stars divide the Moon's path into 27 nakshatras of 13°20′, each in 4 padas of 3°20′. Chitra spans 173°20′–186°40′; the Moon entered its pada 4 at 183°20′. It leaves at 08:00, for Swati.

Add the Sun's and the Moon's places among the stars: 44.6° + 185.9° = 230.5°. The sum, cut into 27 parts of 13°20′, gives the yoga: 226°40′–240°00′ is the 18th, Variyana. It ends at 23:36, then Parigha.

A karana is half a tithi: 6° of the Moon's lead, so the first half of Dwadashi is Bava and the second Balava. Bava ended at 23:29 Fri, when the lead reached 138°; Balava runs until 12:13.

A Hindu day runs from one sunrise to the next, not midnight to midnight. This one runs 06:35 to 06:36 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: Vrishabha gives Jyeshtha. The Sun enters Mithuna on 15 Jun, inside the month. The next new moon, 16 Jun, finds it in Mithuna and begins Ashadha.

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 18 May, with the Sun in Vrishabha, began Jyeshtha. This Shukla paksha reads Jyeshtha in both counts.

A samvat year begins with Chaitra, the month whose new moon finds the Sun in Meena: 20 Mar 2015, 06:36 Fri. Since then the Sun has moved 69.2° round the stars. Vikram Samvat numbers that year 2072; Shaka Samvat numbers it 1937.