Panchang in Sevan, Gegharkunik, Armenia Sat 14 Dec 1963

Shiva’s worship centres on nishitha, the midnight muhurta. Chaturdashi runs from 01:04 on Sat 14 Dec to 03:40 on Sun 15 Dec, touching nishitha on both nights. The Nirnayasindhu takes the night it holds more of: Sat 14 Dec. 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: 336°–348° is the 29th, Krishna Chaturdashi. A day takes the tithi in force at its sunrise, 08:14 here. Trayodashi ended at 01:04, before it. Chaturdashi ends at 03:40 Sun, when the lead reaches 348°. The lead passed 180° at the full moon of 1 Dec, so the Moon is waning: Krishna paksha.

The night of Fri 13 Dec ran from sunset 17:33 Fri to sunrise 08:14, 14 h 41 m. Cut into 15 muhurtas of 58 m, its 14th is Brahma Muhurta, the one before the last.

Daylight here, 08:14 to 17:33, splits into 8 choghadiyas of 1 h 9 m. Their names follow a fixed order that starts from the weekday, and each name is counted good, neutral or bad.

The night here, 17:33 to 08:15 Sun, splits into 8 choghadiyas of 1 h 50 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′. Anuradha spans 213°20′–226°40′; the Moon entered its pada 2 at 216°40′. It leaves at 03:10 Sun, for Jyeshtha.

Add the Sun's and the Moon's places among the stars: 238.1° + 217.3° = 455.4°, one full turn and 95.4°. Past the turn, cut into 27 parts of 13°20′, it gives the yoga: 93°20′–106°40′ is the 8th, Dhriti. It ends at 05:13 Sun, then Shula.

A karana is half a tithi: 6° of the Moon's lead, so the first half of Chaturdashi is Vishti and the second Shakuni. Vishti runs until 14:23, when the lead reaches 342°; Shakuni until 03:40 Sun.

A Hindu day runs from one sunrise to the next, not midnight to midnight. This one runs 08:14 to 08:15 Sun, so the hours after midnight still belong to Shaniwara.

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: Tula gives Kartika. The Sun enters Vrishchika on 16 Nov and Dhanu on 16 Dec, both inside the month. The next new moon, 16 Dec, finds it in Dhanu and begins Pausha.

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 16 Dec, with the Sun in Dhanu, begins Pausha. Until then this Krishna paksha reads Pausha here, and Kartika in the amanta count.

A samvat year begins with Chaitra, the month whose new moon finds the Sun in Meena: 25 Mar 1963, 16:09 Mon. Since then the Sun has moved 257.3° round the stars. Vikram Samvat numbers that year 2020; Shaka Samvat numbers it 1885.