diff --git a/docs/timeline/index.html b/docs/timeline/index.html
index cfaee114..b69d05bd 100644
--- a/docs/timeline/index.html
+++ b/docs/timeline/index.html
@@ -1439,15 +1439,21 @@ document.getElementById('myTimeline').onclick = function (event) {
     </tr>
 
      <tr>
-      <td>zoomIn(percentage)</td>
+      <td>zoomIn(percentage [, options])</td>
       <td>none</td>
-      <td>Zoom in the current visible window. The parameter <code>percentage</code> can be a <code>Number</code> and must be between 0 and 1. If the parameter value of <code>percentage</code> is null, the window will be left unchanged.
+      <td>Zoom in the current visible window. The parameter <code>percentage</code> can be a <code>Number</code> and must be between 0 and 1. If the parameter value of <code>percentage</code> is null, the window will be left unchanged. Available options:
+        <ul>
+          <li><code>animation: boolean or {duration: number, easingFunction: string}</code><br>If true (default) or an Object, the range is animated smoothly to the new window. An object can be provided to specify duration and easing function. Default duration is 500 ms, and default easing function is <code>'easeInOutQuad'</code>. Available easing functions: <code>"linear"</code>, <code>"easeInQuad"</code>, <code>"easeOutQuad"</code>, <code>"easeInOutQuad"</code>, <code>"easeInCubic"</code>, <code>"easeOutCubic"</code>, <code>"easeInOutCubic"</code>, <code>"easeInQuart"</code>, <code>"easeOutQuart"</code>, <code>"easeInOutQuart"</code>, <code>"easeInQuint"</code>, <code>"easeOutQuint"</code>, <code>"easeInOutQuint"</code>.</li>
+        </ul>
       </td>
     </tr>
     <tr>
-      <td>zoomOut(percentage)</td>
+      <td>zoomOut(percentage [, options])</td>
       <td>none</td>
-      <td>Zoom out the current visible window. The parameter <code>percentage</code> can be a <code>Number</code> and must be between 0 and 1. If the parameter value of <code>percentage</code> is null, the window will be left unchanged.
+      <td>Zoom out the current visible window. The parameter <code>percentage</code> can be a <code>Number</code> and must be between 0 and 1. If the parameter value of <code>percentage</code> is null, the window will be left unchanged. Available options:
+        <ul>
+          <li><code>animation: boolean or {duration: number, easingFunction: string}</code><br>If true (default) or an Object, the range is animated smoothly to the new window. An object can be provided to specify duration and easing function. Default duration is 500 ms, and default easing function is <code>'easeInOutQuad'</code>. Available easing functions: <code>"linear"</code>, <code>"easeInQuad"</code>, <code>"easeOutQuad"</code>, <code>"easeInOutQuad"</code>, <code>"easeInCubic"</code>, <code>"easeOutCubic"</code>, <code>"easeInOutCubic"</code>, <code>"easeInQuart"</code>, <code>"easeOutQuart"</code>, <code>"easeInOutQuart"</code>, <code>"easeInQuint"</code>, <code>"easeOutQuint"</code>, <code>"easeInOutQuint"</code>.</li>
+        </ul>
       </td>
     </tr>
 
diff --git a/lib/timeline/Core.js b/lib/timeline/Core.js
index 0d42edf5..01bf3993 100644
--- a/lib/timeline/Core.js
+++ b/lib/timeline/Core.js
@@ -708,8 +708,15 @@ Core.prototype.getWindow = function() {
 /**
  * Zoom in the window such that given time is centered on screen.
  * @param {Number} percentage - must be between [0..1]
+ * @param {Object} [options]  Available options:
+ *                                `animation: boolean | {duration: number, easingFunction: string}`
+ *                                    If true (default), the range is animated
+ *                                    smoothly to the new window. An object can be
+ *                                    provided to specify duration and easing function.
+ *                                    Default duration is 500 ms, and default easing
+ *                                    function is 'easeInOutQuad'.
  */
-Core.prototype.zoomIn = function(percentage) {
+Core.prototype.zoomIn = function(percentage, options) {
   if (!percentage || percentage < 0 || percentage > 1) return
   var range = this.getWindow();
   var start = range.start.valueOf();
@@ -720,17 +727,21 @@ Core.prototype.zoomIn = function(percentage) {
   var newStart = start + distance;
   var newEnd = end - distance;
 
-  this.setWindow({
-    start   : newStart,
-    end     : newEnd
-  });
+  this.setWindow(newStart, newEnd, options);
 };
 
 /**
  * Zoom out the window such that given time is centered on screen.
  * @param {Number} percentage - must be between [0..1]
+ * @param {Object} [options]  Available options:
+ *                                `animation: boolean | {duration: number, easingFunction: string}`
+ *                                    If true (default), the range is animated
+ *                                    smoothly to the new window. An object can be
+ *                                    provided to specify duration and easing function.
+ *                                    Default duration is 500 ms, and default easing
+ *                                    function is 'easeInOutQuad'.
  */
-Core.prototype.zoomOut = function(percentage) {
+Core.prototype.zoomOut = function(percentage, options) {
   if (!percentage || percentage < 0 || percentage > 1) return
   var range = this.getWindow();
   var start = range.start.valueOf();
@@ -739,10 +750,7 @@ Core.prototype.zoomOut = function(percentage) {
   var newStart = start - interval * percentage / 2;
   var newEnd = end + interval * percentage / 2;
 
-  this.setWindow({
-    start   : newStart,
-    end     : newEnd
-  });
+  this.setWindow(newStart, newEnd, options);
 };
 
 /**