| Date | Purnima | Tithi (local) | Notes |
|---|---|---|---|
| Friday, January 22, 2027 | Pausha Purnima Vrat | Jan 21, 4:01 PM → Jan 22, 12:17 PM | Vrat & Snan-Daan same day |
| Saturday, February 20, 2027 | Magha Purnima Vrat | Feb 20, 2:30 AM → Feb 20, 11:24 PM | Vrat & Snan-Daan same day |
| Monday, March 22, 2027 | Phalguna Purnima Vrat | Mar 21, 12:52 PM → Mar 22, 10:44 AM | Vrat & Snan-Daan same day |
| Tuesday, April 20, 2027 | Chaitra Purnima Vrat | Apr 20, 12:22 AM → Apr 20, 11:27 PM | Vrat & Snan-Daan same day |
| Wednesday, May 19, 2027 | Vaishakha Purnima Vrat | May 19, 11:33 AM → May 20, 11:59 AM | Snan-Daan (Udaya): May 20 |
| Friday, June 18, 2027 | Jyeshtha Purnima Vrat | Jun 18, 12:05 AM → Jun 19, 1:44 AM | Vrat & Snan-Daan same day |
| Sunday, July 18, 2027 | Ashadha Purnima Vrat | Jul 17, 2:19 PM → Jul 18, 4:45 PM | Vrat & Snan-Daan same day |
| Monday, August 16, 2027 | Shravana Purnima Vrat | Aug 16, 5:59 AM → Aug 17, 8:29 AM | Snan-Daan (Udaya): Aug 17 |
| Wednesday, September 15, 2027 | Bhadrapada Purnima Vrat | Sep 14, 10:19 PM → Sep 16, 12:04 AM | Vrat & Snan-Daan same day |
| Friday, October 15, 2027 | Ashwina Purnima Vrat | Oct 14, 2:20 PM → Oct 15, 2:47 PM | Vrat & Snan-Daan same day |
| Saturday, November 13, 2027 | Kartika Purnima Vrat | Nov 13, 4:26 AM → Nov 14, 3:26 AM | Vrat & Snan-Daan same day |
| Monday, December 13, 2027 | Margashirsha Purnima Vrat | Dec 12, 6:26 PM → Dec 13, 4:09 PM | Vrat & Snan-Daan same day |
Vrat / Satyanarayan puja on the day Purnima prevails at local midday; Snan-Daan on the Udaya-tithi day.
The Moon is at full strength on Purnima — its influence on the mind (Moon) is intense, hence the vrat's restraint and the Moon arghya; the most auspicious day for Vishnu puja and the Satyanarayan katha (Skanda Purana, Reva Khanda) — the katha may be held on any day but Purnima and the Sankranti are best; the fruit of the Purnima bath (Ganga-Yamuna-Narmada) and charity is multiplied.
The vrat rule: the Purnima by the udaya tithi or moonrise-vyapini — the fast on the udaya tithi day, the Satyanarayan katha and Moon arghya on the evening when the Purnima is present at moonrise (usually the same day; sometimes a day earlier — the list above follows the udaya rule, choose the katha evening from the tithi window); paran after seeing the Moon or the next morning.
12 in UK (London). Lunar months do not align with the calendar year, so the count can be 11 or 13.
1 of the 12 dates differ from India for London, because the tithi is judged at the local moment (sunrise/moonrise/Pradosh) and UK is hours away from India in time.
The katha may be held on any auspicious day (housewarming, wedding, birthday, the fulfilment of a vow) — but Purnima, the Sankranti, Ekadashi and Thursday are best; on Purnima both Vishnu-Lakshmi and the Moon are strong; if one has vowed a monthly katha, on the evening of every Purnima; if there is no priest anyone in the family may read it.
In the Satyanarayan katha the prasad is 'savaya' (sava pav/sava kilo/sava paanch) — a little more than the whole — a symbol of gratitude and increase; in the katha the merchant Sadhu suffered for forgetting his vow, hence the vowed prasad is savaya; the measure of the panjiri (semolina-ghee-sugar-banana-Tulsi), the panchamrit too is sava.
Yes — there is no rice ban on Purnima as on Ekadashi; fruit in the vrat (fruit-milk-sabudana-makhana), kheer-poori-sabzi-rice after seeing the Moon; waterless only for the healthy and vowed; the prasad (panjiri-panchamrit) first.