Panchang in Sevan, Gegharkunik, Armenia Thu 17 Sep 2015

Ganesha’s puja is done at madhyahna, the middle fifth of the day. Chaturthi runs from 18:31 on Wed 16 Sep to 20:50 on Thu 17 Sep, so only Thursday’s madhyahna (11:39–14:08) falls within it.

Ganesh Chaturthi: every date in Sevan

The Moon gains on the Sun about 12° a day. Each 12° of lead is one tithi: 36°–48° is the 4th, Shukla Chaturthi. A day takes the tithi in force at its sunrise, 06:42 here. Tritiya ended at 18:31 Wed, before it. Chaturthi ends at 20:50, when the lead reaches 48°. The lead passed 0° at the new moon of 13 Sep, so the Moon is waxing: Shukla paksha.

The night of Wed 16 Sep ran from sunset 19:08 Wed to sunrise 06:42, 11 h 34 m. Cut into 15 muhurtas of 46 m, its 14th is Brahma Muhurta, the one before the last.

Daylight here, 06:42 to 19:06, splits into 8 choghadiyas of 1 h 33 m. Their names follow a fixed order that starts from the weekday, and each name is counted good, neutral or bad.

The night here, 19:06 to 06:43 Fri, splits into 8 choghadiyas of 1 h 27 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′. Swati spans 186°40′–200°00′; the Moon entered its pada 2 at 190°. It leaves at 00:01 Fri, for Vishakha.

Add the Sun's and the Moon's places among the stars: 149.8° + 191.4° = 341.2°. The sum, cut into 27 parts of 13°20′, gives the yoga: 333°20′–346°40′ is the 26th, Indra. It ends at 16:51, then Vaidhriti.

A karana is half a tithi: 6° of the Moon's lead, so the first half of Chaturthi is Vanija and the second Vishti. Vanija runs until 07:43, when the lead reaches 42°; Vishti until 20:50.

A Hindu day runs from one sunrise to the next, not midnight to midnight. This one runs 06:42 to 06:43 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: Simha gives Bhadrapada. The Sun enters Kanya on 17 Sep, inside the month. The next new moon, 13 Oct, finds it in Kanya and begins Ashwina.

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 13 Sep, with the Sun in Simha, began Bhadrapada. This Shukla paksha reads Bhadrapada in both counts.

A samvat year begins with Chaitra, the month whose new moon finds the Sun in Meena: 20 Mar 2015, 13:36 Fri. Since then the Sun has moved 174.4° round the stars. Vikram Samvat numbers that year 2072; Shaka Samvat numbers it 1937.