Panchang in Ipameri, Goiás, Brazil Sun 12 Apr 1964

Amavasya follows the tithi at sunrise. Amavasya runs from 12:28 on Sat 11 Apr to 09:37 on Sun 12 Apr, so it holds sunrise only on Sun 12 Apr, at 06:21. No text giving Amavasya’s time was found; sunrise is Tithika’s convention.

Amavasya: every date in Ipameri

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, 06:21 here. Chaturdashi ended at 12:28 Sat, before it. Amavasya ends at 09:37, when the lead reaches 360°. The lead passed 180° at the full moon of 27 Mar, so the Moon is waning: Krishna paksha.

The night of Sat 11 Apr ran from sunset 18:06 Sat to sunrise 06:21, 12 h 15 m. Cut into 15 muhurtas of 49 m, its 14th is Brahma Muhurta, the one before the last.

Daylight here, 06:21 to 18:05, splits into 8 choghadiyas of 1 h 28 m. Their names follow a fixed order that starts from the weekday, and each name is counted good, neutral or bad.

The night here, 18:05 to 06:21 Mon, splits into 8 choghadiyas of 1 h 32 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 4 at 356°40′. It leaves at 10:48, for Ashwini.

Add the Sun's and the Moon's places among the stars: 359.1° + 357.3° = 716.4°, one full turn and 356.4°. Past the turn, cut into 27 parts of 13°20′, it gives the yoga: 346°40′–360°00′ is the 27th, Vaidhriti. It ends at 11:50, then Vishkambha.

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 23:05 Sat, when the lead reached 354°; Nagava runs until 09:37.

A Hindu day runs from one sunrise to the next, not midnight to midnight. This one runs 06:21 to 06:21 Mon, so the hours after midnight still belong to Raviwara.

A month normally holds one sankranti, the Sun's entry into a new rashi. From 13 Mar 23:13 Fri to 12 Apr 09:37 the Sun stayed in Meena, entering Mesha at 13 Apr 03:22 Mon, after the new moon. A month with no sankranti is Adhika Chaitra, before Chaitra itself.

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 12 Apr, with the Sun in Meena, begins Chaitra (Adhik). Until then this Krishna paksha reads Chaitra (Adhik) here, and Chaitra (Adhik) in the amanta count.

A samvat year begins with Chaitra, the month whose new moon finds the Sun in Meena: 13 Mar 1964, 23:13 Fri. Since then the Sun has moved 28.9° round the stars. Vikram Samvat numbers that year 2021; Shaka Samvat numbers it 1886.