jquery - JavaScript incorrect time showing between two time -

i have tried show time between 2 time while page load. please check below code -

var start = document.getelementbyid("start").value;  var end = document.getelementbyid("end").value;    function hourdiff(start, end) {      start = start.split(":");      end = end.split(":");      var startdate = new date(0, 0, 0, start[0], start[1], 0);      var enddate = new date(0, 0, 0, end[0], end[1], 0);      var diff = enddate.gettime() - startdate.gettime();      var hours = math.floor(diff / 1000 / 60 / 60);      diff -= hours * 1000 * 60 * 60;      var minutes = math.floor(diff / 1000 / 60);            return (hours < 9 ? "0" : "") + hours + ":" + (minutes < 9 ? "0" : "") + minutes;      //settimeout(function(){hourdiff(start, end)},500);  }    document.getelementbyid("diff").value = hourdiff(start, end);

<input id="start" value="20:00"> <!-- 08.00 pm -->  <input id="end" value="09:30"> <!-- 09.30 -->    <input id="diff">

i have used start time 20.00 , end time 09.30 different between 2 time = 13.30 hours showing wrong hour. please check , let me know.

edit:

also want how many hour:minute:second left

if dates in same format hh:mm, why don't try suggestion.

it quite simple:

var hours = end[0] - start[0]; if(start[0] > end[0]) {     hours = 24 + hours; }  var minutes = end[1] - start[1]; if(start[1] > end[1]) {     minutes = 60 + minutes;     if(hours == 0) {         hours = 23;     } else {         hours--;     } } 

i substract them each other , react if start value bigger end value. fiddle: https://jsfiddle.net/rvwr9h0w/1/

edit

i found simpler solution, because of shotgun ninja's post:

https://jsfiddle.net/rvwr9h0w/4/

var enddate = new date(0, 0, (start > end)?1:0 , end[0], end[1], end[2]); 

if start time bigger end time, set end date 1 day ahead.