If you don't need to know the exact date of an event, or only want to use the month and year, it is possible to enter partial dates in the Date field.
This includes both a missing day and a missing day and month. This will be reflected in configured web surveys, visit forms, and repeating data forms and their printables.
Learn more about validating partial dates in the article Validating partial dates NK/MM/YYYY and Entering and managing partial dates in Castor CDMS.