Panchang in Diffa, Niger Tue 29 May 2018

Purnima follows the tithi at sunrise. Purnima runs from 14:10 on Mon 28 May to 15:19 on Tue 29 May, so it holds sunrise only on Tue 29 May, at 05:41. No text giving Purnima’s time was found; sunrise is Tithika’s convention.

Purnima: every date in Diffa

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, 05:41 here. Chaturdashi ended at 14:10 Mon, before it. Purnima ends at 15:19, when the lead reaches 180°. The lead passed 0° at the new moon of 15 May, so the Moon is waxing: Shukla paksha.

The night of Mon 28 May ran from sunset 18:32 Mon to sunrise 05:41, 11 h 9 m. Cut into 15 muhurtas of 44 m, its 14th is Brahma Muhurta, the one before the last.

Daylight here, 05:41 to 18:32, 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, 18:32 to 05:41 Wed, splits into 8 choghadiyas of 1 h 23 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′. Anuradha spans 213°20′–226°40′; the Moon entered its pada 2 at 216°40′. It leaves at 20:25, for Jyeshtha.

Add the Sun's and the Moon's places among the stars: 43.7° + 219.1° = 262.8°. The sum, cut into 27 parts of 13°20′, gives the yoga: 253°20′–266°40′ is the 20th, Shiva. It ends at 12:42, then Siddha.

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 02:41, when the lead reached 174°; Bava runs until 15:19.

A Hindu day runs from one sunrise to the next, not midnight to midnight. This one runs 05:41 to 05:41 Wed, so the hours after midnight still belong to Mangalawara.

A month normally holds one sankranti, the Sun's entry into a new rashi. From 15 May 12:47 Tue to 13 Jun 20:43 Wed the Sun stayed in Vrishabha, entering Mithuna at 15 Jun 07:06 Fri, after the new moon. A month with no sankranti is Adhika Jyeshtha, before Jyeshtha 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 15 May, with the Sun in Vrishabha, began Jyeshtha (Adhik). This Shukla paksha reads Jyeshtha (Adhik) in both counts.

A samvat year begins with Chaitra, the month whose new moon finds the Sun in Meena: 17 Mar 2018, 14:11 Sat. Since then the Sun has moved 70.9° round the stars. Vikram Samvat numbers that year 2075; Shaka Samvat numbers it 1940.