Nirjala Ekadashi

Bhima, alone among the Pandavas, could not bear to fast. His appetite was legendary. He asked Vyasa for a way to gain the merit of all twenty-four Ekadashis without keeping them all. Vyasa gave him this one, on condition it be kept absolutely: no food and no water. Bhima kept it and collapsed at the end, which is why it carries his name.

A complete fast from sunrise until the Dwadashi parana next morning, without water. Water is instead given away, pyaus and water stalls are set up, earthen pots, fans, umbrellas and slippers donated. Vishnu is worshipped.

Nothing during the fast. Parana is broken with water, then simple sattvik food, usually fruit, then khichdi.

Widely kept across North and West India; less prominent in the south, where the Ekadashi calendar is followed but this one isn't singled out as strongly.