Devpodhi Ekadashi falls on the eleventh day of the bright half of the month of Ashada in
North Indian Hindu Calendar. This is the first day of the ‘
Chaturmaas (four months of rainy season)’.
Lord Vishnu retires to the Kshirsagar (milky ocean) on this day. Observation of fast and other religious rites commences from this date and lasts till the end of the four months. It is also known as Shayani Ekadashi.
[Source all india (80) 21-Apr-05]