Panchang in Sevan, Gegharkunik, Armenia Sat 13 Aug 2011

The rakhi is tied in aparahna, the fourth fifth of the day, outside bhadra. Purnima runs from 23:15 on Fri 12 Aug to 23:57 on Sat 13 Aug, so only Saturday’s aparahna (15:27–18:14) falls within it. Every reading takes that day.

Raksha Bandhan: every date in Sevan

Purnima follows the tithi at sunrise. Purnima runs from 23:15 on Fri 12 Aug to 23:57 on Sat 13 Aug, so it holds sunrise only on Sat 13 Aug, at 07:08. No text giving Purnima’s time was found; sunrise is Tithika’s convention.

Purnima: every date in Sevan

The Moon gains on the Sun about 12° a day. Each 12° of lead is one tithi: 168°–180° is the 15th, Shukla Purnima. A day takes the tithi in force at its sunrise, 07:08 here. Chaturdashi ended at 23:15 Fri, before it. Purnima ends at 23:57, when the lead reaches 180°. The lead passed 0° at the new moon of 30 Jul, so the Moon is waxing: Shukla paksha.

The night of Fri 12 Aug ran from sunset 21:02 Fri to sunrise 07:08, 10 h 6 m. Cut into 15 muhurtas of 40 m, its 14th is Brahma Muhurta, the one before the last.

Daylight here, 07:08 to 21:01, splits into 8 choghadiyas of 1 h 44 m. Their names follow a fixed order that starts from the weekday, and each name is counted good, neutral or bad.

The night here, 21:01 to 07:09 Sun, splits into 8 choghadiyas of 1 h 16 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′. Shravana spans 280°00′–293°20′; the Moon entered its pada 3 at 286°40′. It leaves at 17:35, for Dhanishtha.

Add the Sun's and the Moon's places among the stars: 116° + 287.8° = 403.8°, one full turn and 43.8°. Past the turn, cut into 27 parts of 13°20′, it gives the yoga: 40°00′–53°20′ is the 4th, Saubhagya. It ends at 23:57, then Shobhana.

A karana is half a tithi: 6° of the Moon's lead, so the first half of Purnima is Vishti and the second Bava. Vishti runs until 11:33, when the lead reaches 174°; Bava until 23:57.

A Hindu day runs from one sunrise to the next, not midnight to midnight. This one runs 07:08 to 07:09 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: Karka gives Shravana. The Sun enters Simha on 17 Aug, inside the month. The next new moon, 29 Aug, 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 30 Jul, with the Sun in Karka, began Shravana. This Shukla paksha reads Shravana in both counts.

A samvat year begins with Chaitra, the month whose new moon finds the Sun in Meena: 3 Apr 2011, 19:32 Sun. Since then the Sun has moved 126.5° round the stars. Vikram Samvat numbers that year 2068; Shaka Samvat numbers it 1933.