diff --git a/docs/timeline/index.html b/docs/timeline/index.html
index 351bb919..edc0f56f 100644
--- a/docs/timeline/index.html
+++ b/docs/timeline/index.html
@@ -1367,7 +1367,7 @@ document.getElementById('myTimeline').onclick = function (event) {
       <td>setCustomTimeTitle(title [, id])</td>
       <td>none</td>
       <td>Adjust the title attribute of a custom time bar.
-        Parameter <code>title</code> is the string to be set as title. Use empty string to hide the title completely.
+        Parameter <code>title</code> is the string or function to be set as title. Use empty string to hide the title completely.
         Parameter <code>id</code> is the id of the custom time bar, and is <code>undefined</code> by default.
       </td>
     </tr>
diff --git a/examples/timeline/other/customTimeBarsTooltip.html b/examples/timeline/other/customTimeBarsTooltip.html
new file mode 100644
index 00000000..0fe62f36
--- /dev/null
+++ b/examples/timeline/other/customTimeBarsTooltip.html
@@ -0,0 +1,95 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Timeline | Show current and custom time bars</title>
+
+  <style type="text/css">
+    body, html {
+      font-family: sans-serif;
+      font-size: 11pt;
+    }
+  </style>
+
+  <script src="../../../dist/vis.js"></script>
+  <link href="../../../dist/vis-timeline-graph2d.min.css" rel="stylesheet" type="text/css" />
+  <script src="../../googleAnalytics.js"></script>
+</head>
+<body>
+
+<p>
+  The Timeline has functions to add multiple custom time bars which can be dragged by the user.
+</p>
+<p>
+  <input type="button" id="add" value="Add custom vertical bar">
+  <input type="text" id="barId" placeholder="custom bar ID">
+</p>
+<p>
+  <input type="button" id="remove" value="Remove custom vertical bar">
+  <input type="text" id="barIndex" value="t1" placeholder="custom bar ID">
+</p>
+<p>
+  <code><strong>timechange</strong></code> event, index: <span id="timechangeBar"></span>, time: <span id="timechangeEvent"></span>
+</p>
+<p>
+  <code><strong>timechanged</strong></code> event, index: <span id="timechangedBar"></span>, time: <span id="timechangedEvent"></span>
+</p><br>
+
+<div id="visualization"></div>
+
+<script type="text/javascript">
+  var container = document.getElementById('visualization');
+  var items = new vis.DataSet();
+  var customDate = new Date();
+  var options = {
+    showCurrentTime: true,
+    start: new Date(Date.now() - 1000 * 60 * 60 * 24),
+    end: new Date(Date.now() + 1000 * 60 * 60 * 24 * 6)
+  };
+  var timeline = new vis.Timeline(container, items, options);
+
+  // Set first time bar
+  customDate = new Date(customDate.getFullYear(), customDate.getMonth(), customDate.getDate() + 1);
+  timeline.addCustomTime(customDate, 't1');
+  timeline.setCustomTimeTitle(function(time){
+      return "I'm t1!";
+  }, "t1");
+
+  document.getElementById('add').onclick = function () {
+    try {
+      customDate = new Date(customDate.getFullYear(), customDate.getMonth(), customDate.getDate() + 1);
+      var barId = document.getElementById('barId').value || undefined;
+      timeline.addCustomTime(customDate, barId);
+        timeline.setCustomTimeTitle(function(time){
+            return "I'm "+barId+"!";
+        }, barId);
+      document.getElementById('barId').value = '';
+    }
+    catch (err) {
+      console.log(err);
+      alert(err);
+    }
+  };
+
+  document.getElementById('remove').onclick = function () {
+    try {
+      timeline.removeCustomTime(document.getElementById('barIndex').value);
+      document.getElementById('barIndex').value = '';
+    }
+    catch (err) {
+      console.log(err);
+      alert(err);
+    }
+  };
+
+  timeline.on('timechange', function (properties) {
+    document.getElementById('timechangeBar').innerHTML = properties.id;
+    document.getElementById('timechangeEvent').innerHTML = properties.time;
+  });
+  timeline.on('timechanged', function (properties) {
+    document.getElementById('timechangedBar').innerHTML = properties.id;
+    document.getElementById('timechangedEvent').innerHTML = properties.time;
+  });
+
+</script>
+</body>
+</html>
\ No newline at end of file
diff --git a/lib/timeline/component/CustomTime.js b/lib/timeline/component/CustomTime.js
index 6a94b2ac..6aa6502a 100644
--- a/lib/timeline/component/CustomTime.js
+++ b/lib/timeline/component/CustomTime.js
@@ -143,6 +143,8 @@ CustomTime.prototype.redraw = function () {
   if (title === undefined) {
     title = locale.time + ': ' + this.options.moment(this.customTime).format('dddd, MMMM Do YYYY, H:mm:ss');
     title = title.charAt(0).toUpperCase() + title.substring(1);
+  } else if (typeof title === "function") {
+    title = title.call(this.customTime);
   }
 
   this.bar.style.left = x + 'px';
