Panchang in Codcod, Western Visayas, Philippines Mon 24 Apr 2017

Shiva’s Pradosh puja is done in pradosha, the 3 muhurtas after sunset. Trayodashi runs from 04:56 on Mon 24 Apr to 02:34 on Tue 25 Apr, so only Monday’s pradosha (17:58–20:17) 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, 05:32 here. Dwadashi ended at 04:56, before it. Trayodashi ends at 02:34 Tue, when the lead reaches 336°. The lead passed 180° at the full moon of 11 Apr, so the Moon is waning: Krishna paksha.

The night of Sun 23 Apr ran from sunset 17:58 Sun to sunrise 05:32, 11 h 34 m. Cut into 15 muhurtas of 46 m, its 14th is Brahma Muhurta, the one before the last.

Daylight here, 05:32 to 17:58, 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 night here, 17:58 to 05:31 Tue, 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 fixed stars divide the Moon's path into 27 nakshatras of 13°20′, each in 4 padas of 3°20′. Uttara Bhadrapada spans 333°20′–346°40′; the Moon entered its pada 1 at 333°20′. It leaves at 02:34 Tue, for Revati.

Add the Sun's and the Moon's places among the stars: 9.8° + 334.1° = 343.9°. The sum, cut into 27 parts of 13°20′, gives the yoga: 333°20′–346°40′ is the 26th, Indra. It ends at 09:51, then Vaidhriti.

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 15:50, when the lead reaches 330°; Vanija until 02:34 Tue.

A Hindu day runs from one sunrise to the next, not midnight to midnight. This one runs 05:32 to 05:31 Tue, so the hours after midnight still belong to Somawara.

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: Meena gives Chaitra. The Sun enters Mesha on 14 Apr, inside the month. The next new moon, 26 Apr, finds it in Mesha and begins Vaishakha.

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, begins Vaishakha. Until then this Krishna paksha reads Vaishakha here, and Chaitra 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 26.3° round the stars. Vikram Samvat numbers that year 2074; Shaka Samvat numbers it 1939.