Track Underage contact based on birthday

Dynamics 365 doesn’t give a functionality to identify under age contacts though it captures the birthday by default. Here is a simple code snippet to switch a flag based on age. We can now simply distinguish under age (<18) contact easily through a view.

SetUnderAgeFlag = function() {
  var birthDate = Xrm.Page.getAttribute('birthdate').getValue();
  if (birthDate  != null)
  {
      var today = new Date();
      var nowyear = today.getFullYear();
      var nowmonth = today.getMonth();
      var nowday = today.getDate();             

      var birthyear = birthDate.getFullYear();
      var birthmonth = birthDate.getMonth();
      var birthday = birthDate.getDate();

      var age = nowyear - birthyear;
      var age_month = nowmonth - birthmonth;
      var age_day = nowday - birthday;

      if ( (age < 18) || ((age==18) && (age_month<0)) || ((age==18) && (age_month==0) && (age_day <0)) )
      {         
         Xrm.Page.getAttribute('new_under18flag').setValue(true);
      }
      else
      {
         Xrm.Page.getAttribute('new_under18flag').setValue(false);
      } 
      Xrm.Page.getAttribute('new_under18flag').setSubmitMode('always');  
  }   
}