(If Mahadvadasi is in force, fasting is prohibited on the Ekadasi, but the observance is done on the Dwadasi. Compound Dwadasi-Mahadwadasi.)
1/. If Ekadasi begins after sunrise and ends before sunrise the next day it is considered Lost, too short, thus not full, and impure. Therefore the next day is called Unmillani Mahadwadasi.
2/. If Dwadasi begins after sunrise and ends before sunrise on the next day (Trayodasi), it is also Lost, and is to be observed as Tri-Sprsa-Mahadwadasi.
3/. If Dwadasi falls on the Sunrise two days in a row the first Dwadasi becomes Vyanjuli Mahadwadasi.
4/. When the following Amavasya or Purnima falls on sunrise two days in a row the preceeding Dwadasi becomes Paksa-Vardhini-Mahadwadasi, Paksa based.
Note::: Special thanks to Jaya Tirtha Caran prabhu from NZ for allowing us to use some of the content from his site to compile these pages.