fixed client latency

app.js

@@ -267,6 +267,7 @@ client.on('connection', function (clientSpark)
 
 	clientSpark.on('client-pong', function (data)
 	{
+		var start = (!_.isUndefined(data) && !_.isUndefined(data.serverTime) ? data.serverTime : clientLatency)
 		var latency = Math.ceil( (_.now() - data.serverTime) / 2 );
 
 		clientSpark.emit('client-latency', { latency: latency });
@@ -275,10 +276,12 @@ client.on('connection', function (clientSpark)
 
 var latencyTimeout = setInterval( function ()
 {
+	clientLatency = _.now();
+
 	client.write({
 		action: 'client-ping',
 		data: {
-			serverTime: _.now()
+			serverTime: clientLatency
 		}
 	});
 }, 5000);