Panchang in Ipameri, Goiás, Brazil Sat 2 May 1981

Shiva’s worship centres on nishitha, the midnight muhurta. Chaturdashi runs from 08:59 on Sat 2 May to 05:15 on Sun 3 May, so only Saturday night’s nishitha (23:44–00:34 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, 06:26 here. Dwadashi ended at 12:22 Fri, before it. Trayodashi ends at 08:59, when the lead reaches 336°. The lead passed 180° at the full moon of 19 Apr, so the Moon is waning: Krishna paksha.

A day takes the tithi in force at its sunrise. Chaturdashi began at 08:59 and ended at 05:15 Sun, between the sunrises of 06:26 and 06:26 Sun. Saturday reads Trayodashi and Sunday reads Amavasya: Chaturdashi is a kshaya tithi here.

The night of Fri 1 May ran from sunset 17:53 Fri to sunrise 06:26, 12 h 33 m. Cut into 15 muhurtas of 50 m, its 14th is Brahma Muhurta, the one before the last.

Daylight here, 06:26 to 17:52, splits into 8 choghadiyas of 1 h 25 m. Their names follow a fixed order that starts from the weekday, and each name is counted good, neutral or bad.

The night here, 17:52 to 06:26 Sun, splits into 8 choghadiyas of 1 h 34 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′. Revati spans 346°40′–360°00′; the Moon entered its pada 2 at 350°. It leaves at 17:53, for Ashwini.

Add the Sun's and the Moon's places among the stars: 18.3° + 352.8° = 371.1°, one full turn and 11.1°. Past the turn, cut into 27 parts of 13°20′, it gives the yoga: 0°00′–13°20′ is the 1st, Vishkambha. It ends at 09:48, then Priti.

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 22:44 Fri, when the lead reached 330°; Vanija runs until 08:59.

A Hindu day runs from one sunrise to the next, not midnight to midnight. This one runs 06:26 to 06:26 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: Meena gives Chaitra. The Sun enters Mesha on 13 Apr, inside the month. The next new moon, 4 May, finds it in Mesha and begins Vaishakha.

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 4 May, with the Sun in Mesha, begins Vaishakha. Until then this Krishna paksha reads Vaishakha here, and Chaitra in the amanta count.

A samvat year begins with Chaitra, the month whose new moon finds the Sun in Meena: 4 Apr 1981, 17:19 Sat. Since then the Sun has moved 26.9° round the stars. Vikram Samvat numbers that year 2038; Shaka Samvat numbers it 1903.