Panchang in Codcod, Western Visayas, Philippines Tue 13 Feb 2018

Shiva’s Pradosh puja is done in pradosha, the 3 muhurtas after sunset. Trayodashi runs from 22:34 on Mon 12 Feb to 01:04 on Wed 14 Feb, so only Tuesday’s pradosha (17:54–20:21) falls within it. No text giving Pradosh Vrat’s time was found; pradosha is Tithika’s convention.

Pradosh Vrat: every date in Codcod

The Moon gains on the Sun about 12° a day. Each 12° of lead is one tithi: 324°–336° is the 28th, Krishna Trayodashi. A day takes the tithi in force at its sunrise, 06:08 here. Dwadashi ended at 22:34 Mon, before it. Trayodashi ends at 01:04 Wed, when the lead reaches 336°. The lead passed 180° at the full moon of 31 Jan, so the Moon is waning: Krishna paksha.

The night of Mon 12 Feb ran from sunset 17:54 Mon to sunrise 06:08, 12 h 14 m. Cut into 15 muhurtas of 48 m, its 14th is Brahma Muhurta, the one before the last.

Daylight here, 06:08 to 17:54, 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, 17:54 to 06:07 Wed, splits into 8 choghadiyas of 1 h 31 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′. Uttara Ashadha spans 266°40′–280°00′; the Moon entered its pada 1 at 266°40′. It leaves at 07:26 Wed, for Shravana.

Add the Sun's and the Moon's places among the stars: 300° + 267.4° = 567.4°, one full turn and 207.4°. Past the turn, cut into 27 parts of 13°20′, it gives the yoga: 200°00′–213°20′ is the 16th, Siddhi. It ends at 17:02, then Vyatipata.

A karana is half a tithi: 6° of the Moon's lead, so the first half of Trayodashi is Garaja and the second Vanija. Garaja runs until 11:51, when the lead reaches 330°; Vanija until 01:04 Wed.

A Hindu day runs from one sunrise to the next, not midnight to midnight. This one runs 06:08 to 06:07 Wed, so the hours after midnight still belong to Mangalawara.

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 13 Feb, inside the month. The next new moon, 16 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 Feb, with the Sun in Kumbha, begins Phalguna. Until then this Krishna paksha reads Phalguna here, and Magha in the amanta count.

A samvat year begins with Chaitra, the month whose new moon finds the Sun in Meena: 28 Mar 2017, 10:57 Tue. Since then the Sun has moved 316.5° round the stars. Vikram Samvat numbers that year 2074; Shaka Samvat numbers it 1939.