Panchang in Thazhecode, Kerala Thu 15 Mar 2018

Shiva’s worship centres on nishitha, the midnight muhurta. Chaturdashi runs from 17:19 on Thu 15 Mar to 18:18 on Fri 16 Mar, so only Thursday night’s nishitha (00:10 Fri–00:58 Fri) falls within it. No text giving Masik Shivratri’s time was found; nishitha is Tithika’s convention.

Masik Shivratri: every date in Thazhecode

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, 06:33 here. Dwadashi ended at 15:45 Wed, before it. Trayodashi ends at 17:19, when the lead reaches 336°. The lead passed 180° at the full moon of 2 Mar, so the Moon is waning: Krishna paksha.

The night of Wed 14 Mar ran from sunset 18:36 Wed to sunrise 06:33, 11 h 57 m. Cut into 15 muhurtas of 47 m, its 14th is Brahma Muhurta, the one before the last.

Daylight here, 06:33 to 18:36, splits into 8 choghadiyas of 1 h 30 m. Their names follow a fixed order that starts from the weekday, and each name is counted good, neutral or bad.

The night here, 18:36 to 06:32 Fri, splits into 8 choghadiyas of 1 h 29 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′. Dhanishtha spans 293°20′–306°40′; the Moon entered its pada 3 at 300°. It leaves at 17:12, for Shatabhisha.

Add the Sun's and the Moon's places among the stars: 330.3° + 301.2° = 631.5°, one full turn and 271.5°. Past the turn, cut into 27 parts of 13°20′, it gives the yoga: 266°40′–280°00′ is the 21st, Siddha. It ends at 21:51, then Sadhya.

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 04:36, when the lead reached 330°; Vanija runs until 17:19.

A Hindu day runs from one sunrise to the next, not midnight to midnight. This one runs 06:33 to 06:32 Fri, so the hours after midnight still belong to Guruwara.

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: Kumbha gives Phalguna. The Sun enters Meena on 14 Mar, inside the month. The next new moon, 17 Mar, finds it in Meena and begins Chaitra.

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 Mar, with the Sun in Meena, begins Chaitra. Until then this Krishna paksha reads Chaitra here, and Phalguna in the amanta count.

A samvat year begins with Chaitra, the month whose new moon finds the Sun in Meena: 28 Mar 2017, 08:27 Tue. Since then the Sun has moved 346.8° round the stars. Vikram Samvat numbers that year 2074; Shaka Samvat numbers it 1939.