Panchang in Ipameri, Goiás, Brazil Thu 10 Sep 2015

Shiva’s Pradosh puja is done in pradosha, the 3 muhurtas after sunset. Trayodashi runs from 21:05 on Wed 9 Sep to 22:59 on Thu 10 Sep, so only Thursday’s pradosha (18:07–20:32) falls within it. No text giving Pradosh Vrat’s time was found; pradosha is Tithika’s convention.

Pradosh Vrat: every date in Ipameri

Shiva’s worship centres on nishitha, the midnight muhurta. Chaturdashi runs from 22:59 on Thu 10 Sep to 01:12 on Sat 12 Sep, holding as much of nishitha on both nights. The Nirnayasindhu then takes the earlier: Thu 10 Sep. No text giving Masik Shivratri’s time was found; nishitha is Tithika’s convention.

Masik Shivratri: every date in Ipameri

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, 06:12 here. Dwadashi ended at 21:05 Wed, before it. Trayodashi ends at 22:59, when the lead reaches 336°. The lead passed 180° at the full moon of 29 Aug, so the Moon is waning: Krishna paksha.

The night of Wed 9 Sep ran from sunset 18:06 Wed to sunrise 06:12, 12 h 6 m. Cut into 15 muhurtas of 48 m, its 14th is Brahma Muhurta, the one before the last.

Daylight here, 06:12 to 18:07, 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 night here, 18:07 to 06:11 Fri, 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 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 2 at 110°. It leaves at 23:03, for Magha.

Add the Sun's and the Moon's places among the stars: 143.3° + 111.5° = 254.8°. The sum, cut into 27 parts of 13°20′, gives the yoga: 253°20′–266°40′ is the 20th, Shiva. It ends at 04:03 Fri, then Siddha.

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 09:59, when the lead reaches 330°; Vanija until 22:59.

A Hindu day runs from one sunrise to the next, not midnight to midnight. This one runs 06:12 to 06:11 Fri, so the hours after midnight still belong to Guruwara.

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: Karka gives Shravana. The Sun enters Simha on 17 Aug, inside the month. The next new moon, 13 Sep, finds it in Simha and begins Bhadrapada.

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 13 Sep, with the Sun in Simha, begins Bhadrapada. Until then this Krishna paksha reads Bhadrapada here, and Shravana in the amanta count.

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 167.9° round the stars. Vikram Samvat numbers that year 2072; Shaka Samvat numbers it 1937.