Untitled

<body>
 <form id = "day">
         start date:
             <input type="date" name="startDate">

          finish date:
             <input type="date" name="endDate">

         <input type="submit" onclick = "myFunction()" value="Calculate!">
     </form>

<p id="paragraph"></p>

<script>
function myFunction() {

var formData = JSON.stringify($("#day").serializeArray());
                   $.ajax({
                       url : '/api/myrequest',
                       datatype : 'json',
                       type : 'post',
                       contentType : 'application/json',
                       data : formData,

                       success : function(data) {

                                alert(data);
                       }
                   });
 }
</script>
</body>