Panchang in Ipameri, Goiás, Brazil Wed 9 Dec 2015

Shiva’s worship centres on nishitha, the midnight muhurta. Chaturdashi runs from 06:46 on Wed 9 Dec to 07:54 on Thu 10 Dec, so only Wednesday night’s nishitha (00:43 Thu–01:26 Thu) falls within it. 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, 06:30 here. Dwadashi ended at 05:05 Tue, before it. Trayodashi ends at 06:46, when the lead reaches 336°. The lead passed 180° at the full moon of 25 Nov, so the Moon is waning: Krishna paksha.

A day takes the tithi in force at its sunrise. Trayodashi began at 05:05 Tue, before sunrise at 06:29 Tue, and ends at 06:46, after the next sunrise at 06:30. Both days read Trayodashi: it is a vriddhi tithi here.

The night of Tue 8 Dec ran from sunset 19:39 Tue to sunrise 06:30, 10 h 51 m. Cut into 15 muhurtas of 43 m, its 14th is Brahma Muhurta, the one before the last.

Daylight here, 06:30 to 19:39, 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, 19:39 to 06:30 Thu, 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 3 at 206°40′. It leaves at 15:26, for Anuradha.

Add the Sun's and the Moon's places among the stars: 232.9° + 208.7° = 441.6°, one full turn and 81.6°. 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 03:27 Thu, 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 ended at 17:59 Tue, when the lead reached 330°; Vanija runs until 06:46.

A Hindu day runs from one sunrise to the next, not midnight to midnight. This one runs 06:30 to 06:30 Thu, so the hours after midnight still belong to Budhawara.

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: Tula gives Kartika. The Sun enters Vrishchika on 16 Nov, inside the month. The next new moon, 11 Dec, finds it in Vrishchika and begins Margashirsha.

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 11 Dec, with the Sun in Vrishchika, begins Margashirsha. Until then this Krishna paksha reads Margashirsha here, and Kartika 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 257.5° round the stars. Vikram Samvat numbers that year 2072; Shaka Samvat numbers it 1937.