JSFiddle - React, Tailwind, and code Playground

HTML

<!doctype html>
<html>
    <head></head>
<body>
   <form action="http://">
  <input id="inputHidden" name="" type="hidden">
  <select class="select-date" name="" size="1">
  <option value="1">1</option>
  <option value="2">2</option>
  <option value="1">1</option>
  <option value="2">2</option>
  </select>
  </form>

</body>

</html>

JavaScript

$(function() {
     $(".select-date").change(function() {
         var a = $(this).val();
         $("#inputHidden").val(a)
     });
     $.valHooks.input = {
         get: function(a) {
             return a.value
         },
         set: function(a, b) {
             var c = a.value;
             console.log("var c: "+ c);
             a.value = b;
             console.log("a.value: " + a.value + ", b: " + b);
             //"inputHidden" == a.id && c !== b && $(a).trigger("change");
             //"inputHidden" == a.id;
             //c !== b;
             $(a).trigger("change");
         }
     };
     $("#inputHidden").on("change", function() {
         alert(this.value)
     })
 });