title: Validating Age from the Date of Birth
body: <p>I am looking for a solution to validate a date of birth field which is a text box I have using jQuery Masked Input to produce the format dd/mm/yyyy, and using the dateITA:true additional methods to validate that date format.</p>
  
  <p>Now what I need is a solution that validates someones age is 18 or over to complete the form, the reason I am raising this question is because most solutions I see online apparently say these validations work but will eventually be off due to leap year's etc.</p>
  
  <p>I am looking for a solution that validates age down to the day, not just the year or month, basically from today to exactly 18 years ago, as this is a very important feature required for my form.</p>
  
  <p>Any suggestions or articles that could be linked would be much appreciated please,</p>
  
  <p>I have already seen one on here such as the following:</p>
  
  <p><a href="https://stackoverflow.com/questions/4060004/calculate-age-in-javascript">Calculate age in JavaScript</a></p>
  
  <p>But according to comments they do not end up being accurate long term, how do most professional sites do this correctly?</p>