Don't use number of times updateClock function is called when calculating clock.

Author: nickygerritsen

webapp/public/js/domjudge.js

@@ -128,8 +128,7 @@ function togglelastruns()
 // start (and end?).
 function updateClock()
 {
-	var curtime = initial+offset;
-	date.setTime(curtime*1000);
+	var curtime = Math.round((new Date().getTime() - clientOffset) / 1000);
 
 	var fmt = "";
 	if ( timeleftelt.innerHTML=='start delayed' || timeleft.innerHTML == 'no contest' ) { // FIXME
@@ -166,7 +165,6 @@ function updateClock()
 	}
 
 	timeleftelt.innerHTML = what + fmt;
-	offset++;
 }
 
 function setCookie(name, value)

webapp/templates/partials/menu_countdown.html.twig

@@ -14,11 +14,11 @@
 
 <script>
     var initial = {{ now }};
+    var localInitial = new Date().getTime();
     var activatetime = {{ contest.activatetime|default(-1) }};
     var starttime = {{ contest.starttime|default(-1) }};
     var endtime = {{ contest.endtime|default(-1) }};
-    var offset = 0;
-    var date = new Date(initial * 1000);
+    var clientOffset = localInitial - new Date(initial * 1000).getTime();
     var timeleftelt = document.getElementById("timeleft");
 
     setInterval(function () {