Date change event in jquery

                $('.datepicker1').datepicker({
                    format: "dd/mm/yyyy"
                }).on('change', function(){
                    $('.datepicker').hide();
                    var date=$(this).val();
                    date=date.split("/");
                    var inputDate=date[2]+'-'+date[1]+'-'+date[0];
                    ageCalculator(inputDate);
                });

              

age calculation

                
                    function ageCalculator(userinput) {
                        
                        var dob = new Date(userinput);
                        if(userinput==null || userinput=='') {
                            
                          return false; 
                        } else {
                        var month_diff = Date.now() - dob.getTime();
                        var age_dt = new Date(month_diff); 
                        var year = age_dt.getUTCFullYear();
                        var age = Math.abs(year - 1970);
                        $('#age').val(age);
                        }
                    }

in view

<input type="text" name="dob" id="dob" value="{$booking->dob}" class="form-control datepicker1" placeholder=""