Panchang in Davinópolis, Maranhão, Brazil Sun 7 Dec 1980

Amavasya follows the tithi at sunrise. Amavasya runs from 10:01 on Sat 6 Dec to 11:35 on Sun 7 Dec, so it holds sunrise only on Sun 7 Dec, at 05:48. No text giving Amavasya’s time was found; sunrise is Tithika’s convention.

Amavasya: every date in Davinópolis

The Moon gains on the Sun about 12° a day. Each 12° of lead is one tithi: 348°–360° is the 30th, Krishna Amavasya. A day takes the tithi in force at its sunrise, 05:48 here. Chaturdashi ended at 10:01 Sat, before it. Amavasya ends at 11:35, when the lead reaches 360°. The lead passed 180° at the full moon of 22 Nov, so the Moon is waning: Krishna paksha.

The night of Sat 6 Dec ran from sunset 18:13 Sat to sunrise 05:48, 11 h 35 m. Cut into 15 muhurtas of 46 m, its 14th is Brahma Muhurta, the one before the last.

Daylight here, 05:48 to 18:14, splits into 8 choghadiyas of 1 h 33 m. Their names follow a fixed order that starts from the weekday, and each name is counted good, neutral or bad.

The night here, 18:14 to 05:48 Mon, splits into 8 choghadiyas of 1 h 26 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′. Jyeshtha spans 226°40′–240°00′; the Moon entered its pada 1 at 226°40′. It leaves at 02:54 Mon, for Mula.

Add the Sun's and the Moon's places among the stars: 231.8° + 229.1° = 460.9°, one full turn and 100.9°. Past the turn, cut into 27 parts of 13°20′, it gives the yoga: 93°20′–106°40′ is the 8th, Dhriti. It ends at 16:06, then Shula.

A karana is half a tithi: 6° of the Moon's lead, so the first half of Amavasya is Chatushpada and the second Nagava. Chatushpada ended at 22:51 Sat, when the lead reached 354°; Nagava runs until 11:35.

A Hindu day runs from one sunrise to the next, not midnight to midnight. This one runs 05:48 to 05:48 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: Tula gives Kartika. The Sun enters Vrishchika on 15 Nov, inside the month. The next new moon, 7 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 7 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: 16 Mar 1980, 15:55 Sun. Since then the Sun has moved 259° round the stars. Vikram Samvat numbers that year 2037; Shaka Samvat numbers it 1902.