Panchang in Progreso, Yucatán, Mexico Wed 31 Jan 2018

Purnima follows the tithi at sunrise. Purnima runs from 10:53 on Tue 30 Jan to 07:26 on Wed 31 Jan, so it holds sunrise only on Wed 31 Jan, at 06:36. No text giving Purnima’s time was found; sunrise is Tithika’s convention.

Purnima: every date in Progreso

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, 06:36 here. Chaturdashi ended at 10:53 Tue, before it. Purnima ends at 07:26, when the lead reaches 180°. The lead passed 0° at the new moon of 16 Jan, so the Moon is waxing: Shukla paksha.

A day takes the tithi in force at its sunrise. Pratipada began at 07:26 and ended at 04:13 Thu, between the sunrises of 06:36 and 06:36 Thu. Wednesday reads Purnima and Thursday reads Dwitiya: Pratipada is a kshaya tithi here.

The night of Tue 30 Jan ran from sunset 17:47 Tue to sunrise 06:36, 12 h 49 m. Cut into 15 muhurtas of 51 m, its 14th is Brahma Muhurta, the one before the last.

Daylight here, 06:36 to 17:48, splits into 8 choghadiyas of 1 h 24 m. Their names follow a fixed order that starts from the weekday, and each name is counted good, neutral or bad.

The night here, 17:48 to 06:36 Thu, 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 fixed stars divide the Moon's path into 27 nakshatras of 13°20′, each in 4 padas of 3°20′. Ashlesha spans 106°40′–120°00′; the Moon entered its pada 1 at 106°40′. It leaves at 03:35 Thu, for Magha.

Add the Sun's and the Moon's places among the stars: 287.5° + 107° = 394.5°, one full turn and 34.5°. Past the turn, cut into 27 parts of 13°20′, it gives the yoga: 26°40′–40°00′ is the 3rd, Ayushmana. It ends at 14:56, then Saubhagya.

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 21:08 Tue, when the lead reached 174°; Bava runs until 07:26.

A Hindu day runs from one sunrise to the next, not midnight to midnight. This one runs 06:36 to 06:36 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: Makara gives Magha. The Sun enters Kumbha on 12 Feb, inside the month. The next new moon, 15 Feb, finds it in Kumbha and begins Phalguna.

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 16 Jan, with the Sun in Makara, began Magha. This Shukla paksha reads Magha in both counts.

A samvat year begins with Chaitra, the month whose new moon finds the Sun in Meena: 27 Mar 2017, 20:57 Mon. Since then the Sun has moved 304° round the stars. Vikram Samvat numbers that year 2074; Shaka Samvat numbers it 1939.