Panchang in Sevan, Gegharkunik, Armenia Sun 10 Sep 1950

Shiva’s worship centres on nishitha, the midnight muhurta. Chaturdashi runs from 09:29 on Sun 10 Sep to 08:14 on Mon 11 Sep, so only Sunday night’s nishitha (23:34–00:19 Mon) falls within it. No text giving Masik Shivratri’s time was found; nishitha is Tithika’s convention.

Masik Shivratri: every date in Sevan

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, 05:34 here. Dwadashi ended at 10:06 Sat, before it. Trayodashi ends at 09:29, when the lead reaches 336°. The lead passed 180° at the full moon of 27 Aug, so the Moon is waning: Krishna paksha.

The night of Sat 9 Sep ran from sunset 18:20 Sat to sunrise 05:34, 11 h 14 m. Cut into 15 muhurtas of 44 m, its 14th is Brahma Muhurta, the one before the last.

Daylight here, 05:34 to 18:18, splits into 8 choghadiyas of 1 h 35 m. Their names follow a fixed order that starts from the weekday, and each name is counted good, neutral or bad.

The night here, 18:18 to 05:35 Mon, 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 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 4 at 116°40′. It leaves at 09:49, for Magha.

Add the Sun's and the Moon's places among the stars: 143.7° + 117.6° = 261.3°. The sum, cut into 27 parts of 13°20′, gives the yoga: 253°20′–266°40′ is the 20th, Shiva. It ends at 14:31, then Siddha.

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 ended at 21:52 Sat, when the lead reached 330°; Vanija runs until 09:29.

A Hindu day runs from one sunrise to the next, not midnight to midnight. This one runs 05:34 to 05:35 Mon, so the hours after midnight still belong to Raviwara.

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: Karka gives Shravana. The Sun enters Simha on 16 Aug, inside the month. The next new moon, 12 Sep, finds it in Simha and begins Bhadrapada.

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 12 Sep, with the Sun in Simha, begins Bhadrapada. Until then this Krishna paksha reads Bhadrapada here, and Shravana in the amanta count.

A samvat year begins with Chaitra, the month whose new moon finds the Sun in Meena: 18 Mar 1950, 18:20 Sat. Since then the Sun has moved 169.4° round the stars. Vikram Samvat numbers that year 2007; Shaka Samvat numbers it 1872.