Nirjala Ekadashi is also known as Pandav Bhim Ekadasi fast. The difference from other Ekadasis and Nirjala is that devotees do not drink water on the day. Ekadasi fasting is dedicated to Lord Vishnu and is observed on the 11th day of a fortnight in a traditional Hindu calendar.
: https://www.hindu-blog.com/2009/05/nirjala-ekadashi-nirjala-ekadasi.html