Panchang in Codcod, Western Visayas, Philippines Mon 20 Feb 1978

Shiva’s Pradosh puja is done in pradosha, the 3 muhurtas after sunset. Trayodashi runs from 04:56 on Mon 20 Feb to 06:51 on Tue 21 Feb, so only Monday’s pradosha (17:56–20:22) 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: 144°–156° is the 13th, Shukla Trayodashi. A day takes the tithi in force at its sunrise, 06:05 here. Dwadashi ended at 04:56, before it. Trayodashi ends at 06:51 Tue, when the lead reaches 156°. The lead passed 0° at the new moon of 7 Feb, so the Moon is waxing: Shukla paksha.

A day takes the tithi in force at its sunrise. Trayodashi began at 04:56, before sunrise at 06:05, and ends at 06:51 Tue, after the next sunrise at 06:05 Tue. Both days read Trayodashi: it is a vriddhi tithi here.

The night of Sun 19 Feb ran from sunset 17:56 Sun to sunrise 06:05, 12 h 9 m. Cut into 15 muhurtas of 48 m, its 14th is Brahma Muhurta, the one before the last.

Daylight here, 06:05 to 17:56, 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, 17:56 to 06:05 Tue, 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′. Punarvasu spans 80°00′–93°20′; the Moon entered its pada 4 at 90°. It leaves at 08:58, for Pushya.

Add the Sun's and the Moon's places among the stars: 307.4° + 91.9° = 399.3°, one full turn and 39.3°. 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 07:28, then Saubhagya.

A karana is half a tithi: 6° of the Moon's lead, so the first half of Trayodashi is Kaulava and the second Taitila. Kaulava runs until 17:57, when the lead reaches 150°; Taitila until 06:51 Tue.

A Hindu day runs from one sunrise to the next, not midnight to midnight. This one runs 06:05 to 06:05 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: Makara gives Magha. The Sun enters Kumbha on 12 Feb, inside the month. The next new moon, 9 Mar, 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 7 Feb, 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: 20 Mar 1977, 02:32 Sun. Since then the Sun has moved 331.9° round the stars. Vikram Samvat numbers that year 2034; Shaka Samvat numbers it 1899.