gistfile1.js

 var validateAgeOlderOrExactly = function(date_string, age_limit_year, age_limit_month) {
    var ageLimitDate, birthDate, today;
    if (age_limit_month == null) {
      age_limit_month = 0;
    }
    today = new Date();
    birthDate = new Date(date_string);
    ageLimitDate = new Date(today.getFullYear() - age_limit_year, today.getMonth() - age_limit_month, today.getDate());
    return birthDate <= ageLimitDate;
  };