Panchang in Sevan, Gegharkunik, Armenia Mon 29 Jan 2018

Shiva’s Pradosh puja is done in pradosha, the 3 muhurtas after sunset. Trayodashi runs from 03:48 on Mon 29 Jan to 00:23 on Tue 30 Jan, so only Monday’s pradosha (18:14–21:01) falls within it. No text giving Pradosh Vrat’s time was found; pradosha is Tithika’s convention.

Pradosh Vrat: every date in Sevan

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, 08:12 here. Dwadashi ended at 03:48, before it. Trayodashi ends at 00:23 Tue, when the lead reaches 156°. The lead passed 0° at the new moon of 17 Jan, so the Moon is waxing: Shukla paksha.

The night of Sun 28 Jan ran from sunset 18:12 Sun to sunrise 08:12, 14 h 0 m. Cut into 15 muhurtas of 56 m, its 14th is Brahma Muhurta, the one before the last.

Daylight here, 08:12 to 18:14, splits into 8 choghadiyas of 1 h 15 m. Their names follow a fixed order that starts from the weekday, and each name is counted good, neutral or bad.

The night here, 18:14 to 08:11 Tue, splits into 8 choghadiyas of 1 h 44 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′. Ardra spans 66°40′–80°00′; the Moon entered its pada 2 at 70°. It leaves at 21:33, for Punarvasu.

Add the Sun's and the Moon's places among the stars: 285.1° + 71.7° = 356.8°. The sum, cut into 27 parts of 13°20′, gives the yoga: 346°40′–360°00′ is the 27th, Vaidhriti. It ends at 13:05, then Vishkambha.

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 14:07, when the lead reaches 150°; Taitila until 00:23 Tue.

A Hindu day runs from one sunrise to the next, not midnight to midnight. This one runs 08:12 to 08:11 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 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 17 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: 28 Mar 2017, 06:57 Tue. Since then the Sun has moved 301.6° round the stars. Vikram Samvat numbers that year 2074; Shaka Samvat numbers it 1939.