Panchang in Ipameri, Goiás, Brazil Sun 28 Apr 1991

Purnima follows the tithi at sunrise. Purnima runs from 17:13 on Sat 27 Apr to 17:58 on Sun 28 Apr, so it holds sunrise only on Sun 28 Apr, at 06:25. No text giving Purnima’s time was found; sunrise is Tithika’s convention.

Purnima: every date in Ipameri

The Moon gains on the Sun about 12° a day. Each 12° of lead is one tithi: 168°–180° is the 15th, Shukla Purnima. A day takes the tithi in force at its sunrise, 06:25 here. Chaturdashi ended at 17:13 Sat, before it. Purnima ends at 17:58, when the lead reaches 180°. The lead passed 0° at the new moon of 14 Apr, so the Moon is waxing: Shukla paksha.

The night of Sat 27 Apr ran from sunset 17:55 Sat to sunrise 06:25, 12 h 30 m. Cut into 15 muhurtas of 50 m, its 14th is Brahma Muhurta, the one before the last.

Daylight here, 06:25 to 17:55, 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 night here, 17:55 to 06:25 Mon, 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 fixed stars divide the Moon's path into 27 nakshatras of 13°20′, each in 4 padas of 3°20′. Swati spans 186°40′–200°00′; the Moon entered its pada 1 at 186°40′. It leaves at 04:54 Mon, for Vishakha.

Add the Sun's and the Moon's places among the stars: 13.9° + 188.3° = 202.2°. The sum, cut into 27 parts of 13°20′, gives the yoga: 200°00′–213°20′ is the 16th, Siddhi. It ends at 02:19 Mon, then Vyatipata.

A karana is half a tithi: 6° of the Moon's lead, so the first half of Purnima is Vishti and the second Bava. Vishti ended at 05:32, when the lead reached 174°; Bava runs until 17:58.

A Hindu day runs from one sunrise to the next, not midnight to midnight. This one runs 06:25 to 06:25 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 14 Apr 16:37 Sun to 14 May 01:35 Tue the Sun stayed in Mesha, entering Vrishabha at 14 May 22:25 Tue, after the new moon. A month with no sankranti is Adhika Vaishakha, before Vaishakha 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 14 Apr, with the Sun in Mesha, began Vaishakha (Adhik). This Shukla paksha reads Vaishakha (Adhik) in both counts.

A samvat year begins with Chaitra, the month whose new moon finds the Sun in Meena: 16 Mar 1991, 05:10 Sat. Since then the Sun has moved 42.4° round the stars. Vikram Samvat numbers that year 2048; Shaka Samvat numbers it 1913.