How to include DOB input in the form and save it in contact info? 

Step 1: Create a Form and choose the date field:

Step 2: Click on settings for the Date / Time field.

3: Change the label name to DOB or Date of Birth.

Step 4: Change the format to YYYY-MM-DD

Step 5: Change the property name and set it as DOB.

Click on Save and you will see your contact’s dob in your contacts details once this form is submitted.