www/countdown.js - allow mocking the current time

www/countdown.js

@@ -1,8 +1,8 @@
 // This is deliberately browser-compatible JS, so we avoid fat arrows etc.
 
 var locale = "EN-GB";
-var now = new Date();
-var nextNewYearUTC = new Date(Date.UTC(now.getFullYear()+1, 0, 1));
+var now = getTimeNow();
+var nextNewYearUTC = new Date(Date.UTC(getTimeNow().getFullYear()+1, 0, 1));
 var secsRemaining = 0;
 var nextZone;
 var counter = document.getElementById("counter");
@@ -12,6 +12,15 @@ var untilDate = document.getElementById("until-date");
 
 var countDownSound = new Audio('get-ready.ogg');
 
+// This function returns the current time - or we can adjust it to a
+// fake time, if we're testing!
+function getTimeNow() {
+  var now = new Date();
+  var offset = 0; // hours
+  
+  return new Date(now.valueOf() + offset*3600000);
+}
+
 // Convert the next new year time to 'date, hours:mins:secs' in the target timezone
 function zoneTime(zone, refTime) {
   return refTime.toLocaleString('EN-US', {
@@ -291,7 +300,7 @@ function handleTick(now) {
 }
 
 function ticker() {
-  var now = new Date();
+  var now = getTimeNow();
   handleTick(now);
 
   var millis = now.getMilliseconds()