Panchang in Ipameri, Goiás, Brazil Sun 17 Sep 2017

Shiva’s Pradosh puja is done in pradosha, the 3 muhurtas after sunset. Trayodashi runs from 06:12 on Sun 17 Sep to 04:38 on Mon 18 Sep, so only Sunday’s pradosha (18:08–20:31) 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, 06:06 here. Ekadashi ended at 08:00 Sat, before it. Dwadashi ends at 06:12, when the lead reaches 324°. The lead passed 180° at the full moon of 6 Sep, so the Moon is waning: Krishna paksha.

A day takes the tithi in force at its sunrise. Trayodashi began at 06:12 and ended at 04:38 Mon, between the sunrises of 06:06 and 06:05 Mon. Sunday reads Dwadashi and Monday reads Chaturdashi: Trayodashi is a kshaya tithi here.

The night of Sat 16 Sep ran from sunset 18:07 Sat to sunrise 06:06, 11 h 59 m. Cut into 15 muhurtas of 47 m, its 14th is Brahma Muhurta, the one before the last.

Daylight here, 06:06 to 18:08, splits into 8 choghadiyas of 1 h 30 m. Their names follow a fixed order that starts from the weekday, and each name is counted good, neutral or bad.

The night here, 18:08 to 06:05 Mon, splits into 8 choghadiyas of 1 h 29 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′. Ashlesha spans 106°40′–120°00′; the Moon entered its pada 3 at 113°20′. It leaves at 15:36, for Magha.

Add the Sun's and the Moon's places among the stars: 150.6° + 114.5° = 265.1°. The sum, cut into 27 parts of 13°20′, gives the yoga: 253°20′–266°40′ is the 20th, Shiva. It ends at 08:40, then Siddha.

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 19:05 Sat, when the lead reached 318°; Taitila runs until 06:12.

A Hindu day runs from one sunrise to the next, not midnight to midnight. This one runs 06:06 to 06:05 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: Simha gives Bhadrapada. The Sun enters Kanya on 16 Sep, inside the month. The next new moon, 20 Sep, finds it in Kanya and begins Ashwina.

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 20 Sep, with the Sun in Kanya, begins Ashwina. Until then this Krishna paksha reads Ashwina here, and Bhadrapada in the amanta count.

A samvat year begins with Chaitra, the month whose new moon finds the Sun in Meena: 27 Mar 2017, 23:57 Mon. Since then the Sun has moved 167.1° round the stars. Vikram Samvat numbers that year 2074; Shaka Samvat numbers it 1939.