Panchang in Sevan, Gegharkunik, Armenia Sun 12 May 1991

Shiva’s worship centres on nishitha, the midnight muhurta. Chaturdashi runs from 14:27 on Sun 12 May to 11:43 on Mon 13 May, so only Sunday night’s nishitha (00:36 Mon–01:15 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, 05:47 here. Dwadashi ended at 16:38 Sat, before it. Trayodashi ends at 14:27, when the lead reaches 336°. The lead passed 180° at the full moon of 29 Apr, so the Moon is waning: Krishna paksha.

The night of Sat 11 May ran from sunset 20:05 Sat to sunrise 05:47, 9 h 42 m. Cut into 15 muhurtas of 38 m, its 14th is Brahma Muhurta, the one before the last.

Daylight here, 05:47 to 20:06, splits into 8 choghadiyas of 1 h 47 m. Their names follow a fixed order that starts from the weekday, and each name is counted good, neutral or bad.

The night here, 20:06 to 05:46 Mon, splits into 8 choghadiyas of 1 h 12 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′. Revati spans 346°40′–360°00′; the Moon entered its pada 4 at 356°40′. It leaves at 08:38, for Ashwini.

Add the Sun's and the Moon's places among the stars: 27.1° + 358.3° = 385.4°, one full turn and 25.4°. Past the turn, cut into 27 parts of 13°20′, it gives the yoga: 13°20′–26°40′ is the 2nd, Priti. It ends at 07:45, then Ayushmana.

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 03:37, when the lead reached 330°; Vanija runs until 14:27.

A Hindu day runs from one sunrise to the next, not midnight to midnight. This one runs 05:47 to 05:46 Mon, so the hours after midnight still belong to Raviwara.

A month normally holds one sankranti, the Sun's entry into a new rashi. From 14 Apr 23:37 Sun to 14 May 08:35 Tue the Sun stayed in Mesha, entering Vrishabha at 15 May 05:25 Wed, after the new moon. A month with no sankranti is Adhika Vaishakha, before Vaishakha itself.

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 14 May, with the Sun in Mesha, begins Vaishakha (Adhik). Until then this Krishna paksha reads Vaishakha (Adhik) here, and Vaishakha (Adhik) in the amanta count.

A samvat year begins with Chaitra, the month whose new moon finds the Sun in Meena: 16 Mar 1991, 12:10 Sat. Since then the Sun has moved 55.6° round the stars. Vikram Samvat numbers that year 2048; Shaka Samvat numbers it 1913.