public int countWeekend(LocalDate startDate, LocalDate endDate) {
        int weekdays = 0;
        if (startDate.isEqual(endDate)) {
            return weekdays;
        }

        while (startDate.isBefore(endDate)) {
            if (DayOfWeek.SATURDAY.equals(startDate.getDayOfWeek())
                    || DayOfWeek.SUNDAY.equals(startDate.getDayOfWeek())) {
                weekdays++;
            }
            startDate = startDate.plusDays(1);
        }

        return weekdays;
    }

@RestController
public class RestWebController {
    
    @Autowired
    WeekendService service;

    @RequestMapping(value = "api/myrequest", method = RequestMethod.POST)
    public ResponseEntity<?> catchPostMapping(
            @DateTimeFormat(pattern="yyyy-MM-dd") LocalDate startDate,
            @DateTimeFormat(pattern="yyyy-MM-dd") LocalDate endDate){
        Weekend weekend = new Weekend();
        int days = service.countWeekend(startDate, endDate);
        weekend.setDays(days);
        return new ResponseEntity<>(days, HttpStatus.OK);
    }

<form id="customerForm">
		<label for="startDate" style="margin-right:5px">Start:</label>
		<input type="date" id="startDate"/>

		<label for="endDate" style="margin-right:5px">End:</label>
		<input type="date" id="endDate"/>

		<button type="submit" class="btn btn-default" style="margin-left:20px; margin-right:5px">Submit</button>
	</form>

$( document ).ready(function() {

  // SUBMIT FORM
    $("#customerForm").submit(function(event) {
    event.preventDefault();
    ajaxPost();
  });


    function ajaxPost(){

      // PREPARE FORM DATA
      var formData = {
        startDate : $("#startDate").val(),
        endDate :  $("#endDate").val()
      }

      // DO POST
      $.ajax({
      type : "post",
      contentType : "application/json",
      url :"api/myrequest",
      data : JSON.stringify(formData),
      dataType : 'json',
      success : function(result) {
        if(result.status == "Done"){
          $("#customerForm").html("<p style='background-color:#7FA7B0; color:white; padding:20px 20px 20px 20px'>" +
                        "Post Successfully! <br>" +
                        "--->  StartDate = " +
                        result.data.startDate + " ,End Date = " + result.data.endDate + "</p>");
        }else{
          $("#customerForm").html("<strong>Error</strong>");
        }
        console.log(result);
      },
      error : function(e) {
        alert("Error!")
        console.log("ERROR: ", e);
      }
    });

    }

})