Pradosham, also known as Pradosh Vrat, is an auspicious day associated with Shiva and Parvati. August 2011 Pradosham dates are August 11 and August 26. Pradosham occurs twice in a Hindu month – once each during the waning (Krishna Paksha) and waxing phase (Shukla Paksha) of the moon.
The Pradosham period is in the evening from 1.5 hours before sunset and 1 hour after sunset. The fast which began at sunrise is broken during the period.
Most devotees make it a point to be present at a Shiva temple or offer prayers at home.