Fasting is a common practice for Hindus, but also a very diverse one. The type of fasting undertaken varies depending not just on region and family but also on the individual. Some Hindus set aside certain days of the month or of the week to fast. Others fast during certain religious holidays, Sivaratri being a common choice.
The method of fasting is also highly individualized. In some cases fasting means no food or water from sunrise to sunset (or some other time frame, depending on the individual) and in others it means water but no food. It can also mean taking only one meal a day, or abstaining from certain foods (meat and eggs being common food items to give up).
A common fast day for Hindus is Ekadasi, the eleventh day of the lunar month.