How can I validate that someone is over 18 from their date of birth?

Question

I am doing validation for Driver\'s Date of birth, it should be minimum of 18 from the current date.

var Dates = $get(\'<%=ui_txtDOB.ClientID %>\');            


        

Answer 1

My approach is to find the date 18 (or any number) years ago from today, then see if that's after (greater) than their dob. By setting all values to date objects it makes the comparison easy.

function is_of_age(dob, age) {
  // dates are all converted to date objects
  var my_dob = new Date(dob);
  var today = new Date();
  var max_dob = new Date(today.getFullYear() - age, today.getMonth(), today.getDate());
  return max_dob.getTime() > my_dob.getTime();
}

Because the Date object can parse strings in a variety of formats, You don't have to worry too much about where dob is coming from. Simply call is_of_age("1980/12/4", 18); or is_of_age("2005-04-17", 13); or basically any string format or numeric that can be parsed as a Date parameter.