How to limit the Date of birth to be at least 18 year ago

[Kal_Lam]

Maybe you could try this out as outlined in the image below:

In the survey tab of your xlsform:

Data entry screen as seen in Enketo: When a wrong entry is made

Data entry screen as seen in Enketo: When a correct entry is made

Reference xlsform:

Calculate Age.xlsx (9.7 KB)