For the date of birth field on lead forms, prevent users from being able to enter text values into the day field so it only accepts integers. Here is an example: https://create.jebbit.com/campaign/j3clztpy/builder?iterationId=ucV
Also, consider making the day field a dropdown between 1 - 31, seeming as that is the most days in a calendar month.
Also, opportunity to add rules in that if a user selects a month that only has 30 days, then only 30 days shown in the dropdown.
Currently, this is a request that Studio has to handle.
