Panchang in Ipameri, Goiás, Brazil Sat 6 Feb 2016

Shiva’s worship centres on nishitha, the midnight muhurta. Chaturdashi runs from 16:32 on Sat 6 Feb to 14:50 on Sun 7 Feb, so only Saturday night’s nishitha (01:04 Sun–01:49 Sun) 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, 07:02 here. Dwadashi ended at 17:38 Fri, before it. Trayodashi ends at 16:32, when the lead reaches 336°. The lead passed 180° at the full moon of 23 Jan, so the Moon is waning: Krishna paksha.

The night of Fri 5 Feb ran from sunset 19:51 Fri to sunrise 07:02, 11 h 11 m. Cut into 15 muhurtas of 44 m, its 14th is Brahma Muhurta, the one before the last.

Daylight here, 07:02 to 19:50, 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 night here, 19:50 to 07:03 Sun, splits into 8 choghadiyas of 1 h 24 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′. Purva Ashadha spans 253°20′–266°40′; the Moon entered its pada 4 at 263°20′. It leaves at 11:54, for Uttara Ashadha.

Add the Sun's and the Moon's places among the stars: 292.9° + 263.9° = 556.8°, one full turn and 196.8°. Past the turn, cut into 27 parts of 13°20′, it gives the yoga: 186°40′–200°00′ is the 15th, Vajra. It ends at 12:15, then Siddhi.

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 05:10, when the lead reached 330°; Vanija runs until 16:32.

A Hindu day runs from one sunrise to the next, not midnight to midnight. This one runs 07:02 to 07:03 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: Dhanu gives Pausha. The Sun enters Makara on 14 Jan, inside the month. The next new moon, 8 Feb, finds it in Makara and begins Magha.

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 8 Feb, with the Sun in Makara, begins Magha. Until then this Krishna paksha reads Magha here, and Pausha 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 317.5° round the stars. Vikram Samvat numbers that year 2072; Shaka Samvat numbers it 1937.