Panchang in Progress, Amur Oblast, Russia Wed 10 May 2017

Buddha Purnima follows the tithi at sunrise. Purnima holds both sunrises, 04:44 on Wed 10 May and 04:42 on Thu 11 May. Over two sunrises the Nirnayasindhu takes the first: Wed 10 May. No text giving Buddha Purnima’s time was found; sunrise is Tithika’s convention.

Buddha Purnima: every date in Progress

Purnima follows the tithi at sunrise. Purnima holds both sunrises, 04:44 on Wed 10 May and 04:42 on Thu 11 May. Over two sunrises the Nirnayasindhu takes the first: Wed 10 May. No text giving Purnima’s time was found; sunrise is Tithika’s convention.

Purnima: every date in Progress

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, 04:44 here. Chaturdashi ended at 04:37, before it. Purnima ends at 06:42 Thu, when the lead reaches 180°. The lead passed 0° at the new moon of 26 Apr, so the Moon is waxing: Shukla paksha.

A day takes the tithi in force at its sunrise. Purnima began at 04:37, before sunrise at 04:44, and ends at 06:42 Thu, after the next sunrise at 04:42 Thu. Both days read Purnima: it is a vriddhi tithi here.

The night of Tue 9 May ran from sunset 19:50 Tue to sunrise 04:44, 8 h 54 m. Cut into 15 muhurtas of 35 m, its 14th is Brahma Muhurta, the one before the last.

Daylight here, 04:44 to 19:52, splits into 8 choghadiyas of 1 h 53 m. Their names follow a fixed order that starts from the weekday, and each name is counted good, neutral or bad.

The night here, 19:52 to 04:42 Thu, splits into 8 choghadiyas of 1 h 6 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 2 at 190°. It leaves at 18:04, for Vishakha.

Add the Sun's and the Moon's places among the stars: 25.3° + 193.3° = 218.6°. The sum, cut into 27 parts of 13°20′, gives the yoga: 213°20′–226°40′ is the 17th, Vyatipata. It ends at 19:40, then Variyana.

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 runs until 17:38, when the lead reaches 174°; Bava until 06:42 Thu.

A Hindu day runs from one sunrise to the next, not midnight to midnight. This one runs 04:44 to 04:42 Thu, so the hours after midnight still belong to Budhawara.

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: Mesha gives Vaishakha. The Sun enters Vrishabha on 15 May, inside the month. The next new moon, 26 May, finds it in Vrishabha and begins Jyeshtha.

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 26 Apr, with the Sun in Mesha, began Vaishakha. This Shukla paksha reads Vaishakha in both counts.

A samvat year begins with Chaitra, the month whose new moon finds the Sun in Meena: 28 Mar 2017, 11:57 Tue. Since then the Sun has moved 41.8° round the stars. Vikram Samvat numbers that year 2074; Shaka Samvat numbers it 1939.