@etrejosm, you could do it as outlined in the image shared below:
In the survey tab of your xlsform:
Data entry screen as seen in Enketo: when a date is outside the range
Data entry screen as seen in Enketo: when a date is inside the range
Data entry screen as seen in Enketo: when a date is outside the range
Reference xlsform:
Date Constraint.xls (37.5 KB)