Implemented activity timer in JS.

public/css/style.css

@@ -496,3 +496,8 @@ hr
 {
   border: 1px solid #3D3D3D;
 }
+
+.activity .isoDate
+{
+  display: none;
+}

public/js/forum.js

@@ -2,4 +2,75 @@
 
 window.onload = function() {
   positionGlowArrow();
+  processMainDates();
+  window.setTimeout(performProcessingMainDates, 1000);
 };
+
+function performProcessingMainDates()
+{
+  if (processMainDates())
+  {
+    window.setTimeout(performProcessingMainDates, 1000);
+  }
+  else
+  {
+    window.setTimeout(performProcessingMainDates, 60000);
+  }
+}
+
+function timeSince(date) {
+    var result = ["", false];
+    var seconds = Math.floor((new Date() - date) / 1000);
+
+    var interval = Math.floor(seconds / 31536000);
+
+    if (interval >= 1) {
+        result[0] = interval + (interval == 1 ? " year ago" : " years ago");
+        return result;
+    }
+    interval = Math.floor(seconds / 2592000);
+    if (interval >= 1) {
+        result[0] = interval + (interval == 1 ? " month ago" : " months ago");
+        return result;
+    }
+    interval = Math.floor(seconds / 86400);
+    if (interval >= 1) {
+        result[0] = interval + (interval == 1 ? " day ago" : " days ago");
+        return result;
+    }
+    interval = Math.floor(seconds / 3600);
+    if (interval >= 1) {
+        result[0] = interval + (interval == 1 ? " hour ago" : " hours ago");
+        return result;
+    }
+    interval = Math.floor(seconds / 60);
+    if (interval >= 1) {
+        result[0] = interval + (interval == 1 ? " minute ago" : " minutes ago");
+        return result;
+    }
+    if (seconds >= 1) {
+      result[0] = Math.floor(seconds) +
+          (seconds == 1 ? " second ago" : " seconds ago");
+      result[1] = true;
+      return result;
+    }
+    return ["less than a second ago", true];
+}
+
+function processMainDates() {
+  var result = false;
+  var threads = document.getElementById("talk-threads").children;
+  for (var i = 0; i < threads.length; i++)
+  {
+    var activity = threads[i].getElementsByClassName("activity")[0];
+    var activityDiv = activity.children[0];
+    var isoDate = activityDiv.children[0].innerHTML;
+    var parsed = Date.parse(isoDate);
+    var timeS = timeSince(parsed);
+    
+    activityDiv.innerHTML = activityDiv.children[0].outerHTML +
+        timeS[0];
+    if (timeS[1]) { result = timeS[1] }
+  }
+  return result;
+}