Shows time the app has been running

core/src/main/scala/spark/SparkContext.scala

@@ -128,6 +128,8 @@ class SparkContext(
   private[spark] val ui = new SparkUI(this)
   ui.bind()
 
+  val startTime = System.currentTimeMillis()
+
   // Add each JAR given through the constructor
   if (jars != null) {
     jars.foreach { addJar(_) }

core/src/main/scala/spark/ui/jobs/IndexPage.scala

@@ -54,7 +54,11 @@ private[spark] class IndexPage(parent: JobProgressUI) {
     val summary: NodeSeq =
      <div>
        <ul class="unstyled">
-          <li>
+         <li>
+           <strong>Duration: </strong>
+           {parent.formatDuration(now - listener.sc.startTime)}
+         </li>
+         <li>
             <strong>CPU time: </strong>
             {parent.formatDuration(listener.totalTime + activeTime)}
           </li>