Jqery validate for birthday

You will need to create a custom routine to add a new Validation function. This will need to be after your two CDN calls and before you have your validation routine.

$.validator.addMethod("minAge", function(value, element, min) {
    var today = new Date();
    var birthDate = new Date(value);
    var age = today.getFullYear() - birthDate.getFullYear();
 
    if (age > min+1) { return true; }
 
    var m = today.getMonth() - birthDate.getMonth();
 
    if (m < 0 || (m === 0 && today.getDate() < birthDate.getDate())) { age--; }
 
    return age >= min;
}, "You are not old enough!");

The next thing you will need to do is to incorporate this into your existing validation functions. Here is the new method

$("form").validate({
    rules: {
        dob: {
            required: true,
            minAge: 13
        }
    },
    messages: {
        dob: {
            required: "Please enter you date of birth.",
            minAge: "You must be at least 13 years old!"
        } 
    }
});

These script blocks were easy to find searching google for jQuery Validate Age
This came from the #1 result Check for a Minimum Age with jQuery Validation | Pete Mall[^]