JQuery возврат NaN на мобильный

Question

Я работаю над вычислениями различий между двумя датами и временем ввода и возврата с помощью appendChild. Проверено на Chrome, Firefox, IE, работает нормально. Но на мобильный возврат NaN.

//...append

$(document).ready(function() {

  //...set default date

  $('#d1, #d2, #t1, #t2').on('change', function(ev) {
    var dl = document.getElementById("diff");
    while (dl.hasChildNodes()) {
      dl.removeChild(dl.lastChild);
    }

    //calculation differences between two date and time
    var date1 = new Date($('#d1').val() + " " + $('#t1').val()).getTime();
    var date2 = new Date($('#d2').val() + " " + $('#t2').val()).getTime();
    append(dl, "Interval ", " from: " + $('#d1').val() + " " + $('#t1').val() + " to: " + $('#d2').val() + " " + $('#t2').val()); //return ok
    var msec = date2 - date1;
    var mins = Math.floor(msec / 60000);
    var hrs = Math.floor(mins / 60);
    var days = Math.floor(hrs / 24);
    var yrs = Math.floor(days / 365);
    append(dl, "In minutes: ", mins + " minutes"); //return NaN
    mins = mins % 60;
    append(dl, "In hours: ", hrs + " hours, " + mins + " minutes"); //return NaN
    hrs = hrs % 24;
    append(dl, "In days: ", days + " days, " + hrs + " hours, " + mins + " minutes"); //return NaN
    days = days % 365;
    append(dl, "In years: ", yrs + " years " + days + " days "); //return NaN
  });

  // trigger change
  $('#d1').change();

});

скрипка: https://jsfiddle.net/user2314737/jr5jkv1p/