Welcome to the community, @mjemal! Maybe you could design your xlsform as outlined below, which should restrict users to select the date from within a specified range:
In the survey tab of your xlsform:
Data entry as seen in Enketo: (when a date is entered outside the range)
Data entry as seen in Enketo: (when a date is entered within the range)
Reference xlsform:
Date Constraints.xls (37.5 KB)
