diff --git a/CHANGES.md b/CHANGES.md
index 5e0e29d56022..7ee7ef5b9047 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,6 +1,10 @@
 Change Log
 ==========
 
+### 1.37 - 2017
+
+* Added `customTags` property to the UrlTemplateImageryProvider to allow custom keywords in the template URL.
+
 ### 1.36 - 2017-08-01
 
 * Breaking changes
diff --git a/Source/Scene/UrlTemplateImageryProvider.js b/Source/Scene/UrlTemplateImageryProvider.js
index 7187182f0700..245a68583a2b 100644
--- a/Source/Scene/UrlTemplateImageryProvider.js
+++ b/Source/Scene/UrlTemplateImageryProvider.js
@@ -132,6 +132,7 @@ define([
      *        source does not support picking features or if you don't want this provider's features to be pickable. Note
      *        that this can be dynamically overridden by modifying the {@link UriTemplateImageryProvider#enablePickFeatures}
      *        property.
+     * @param {Object} [options.customTags] Allow to replace custom keywords in the URL template. The object must have strings as keys and functions as values.
      *
      *
      * @example
@@ -157,6 +158,15 @@ define([
      *          'width=256&height=256',
      *    rectangle : Cesium.Rectangle.fromDegrees(96.799393, -43.598214999057824, 153.63925700000001, -9.2159219997013)
      * });
+     * // Using custom tags in your template url.
+     * var custom = new Cesium.UrlTemplateImageryProvider({
+     *    url : 'https://yoururl/{time}/{z}/{y}/{x}.png',
+     *    customTags : {
+     *        '{time}': function(imageryProvider, x, y , level) {
+     *            return '20171231'
+     *        }
+     *    }
+     * });
      *
      * @see ArcGisMapServerImageryProvider
      * @see BingMapsImageryProvider
@@ -568,6 +578,15 @@ define([
             }
             that._credit = credit;
 
+            if (properties.customTags) {
+                for (var tag in properties.customTags) {
+                    if (properties.customTags.hasOwnProperty(tag)) {
+                        tags[tag] = properties.customTags[tag]; //eslint-disable-line no-use-before-define
+                        pickFeaturesTags[tag] = properties.customTags[tag]; //eslint-disable-line no-use-before-define
+                    }
+                }
+            }
+
             that._urlParts = urlTemplateToParts(that._url, tags); //eslint-disable-line no-use-before-define
             that._pickFeaturesUrlParts = urlTemplateToParts(that._pickFeaturesUrl, pickFeaturesTags); //eslint-disable-line no-use-before-define
             return true;
diff --git a/Specs/Scene/UrlTemplateImageryProviderSpec.js b/Specs/Scene/UrlTemplateImageryProviderSpec.js
index b8befc7068a8..b166e49550b0 100644
--- a/Specs/Scene/UrlTemplateImageryProviderSpec.js
+++ b/Specs/Scene/UrlTemplateImageryProviderSpec.js
@@ -634,6 +634,34 @@ defineSuite([
         });
     });
 
+    it('uses custom tags', function() {
+        var provider = new UrlTemplateImageryProvider({
+            url: 'made/up/tms/server/{custom1}/{custom2}/{z}/{y}/{x}.PNG',
+            tilingScheme: new GeographicTilingScheme(),
+            maximumLevel: 6,
+            customTags: {
+                '{custom1}': function() { return 'foo';},
+                '{custom2}': function() { return 'bar';}
+            }
+        });
+
+        return pollToPromise(function() {
+            return provider.ready;
+        }).then(function() {console.error('spyon');
+            spyOn(loadImage, 'createImage').and.callFake(function(url, crossOrigin, deferred) {
+                expect(url).toEqual('made/up/tms/server/foo/bar/2/1/3.PNG');
+
+                // Just return any old image.
+                loadImage.defaultCreateImage('Data/Images/Red16x16.png', crossOrigin, deferred);
+            });
+
+            return provider.requestImage(3, 1, 2).then(function(image) {
+                expect(loadImage.createImage).toHaveBeenCalled();
+                expect(image).toBeInstanceOf(Image);
+            });
+        });
+    });
+
     describe('pickFeatures', function() {
         it('returns undefined when enablePickFeatures is false', function() {
             var provider = new UrlTemplateImageryProvider({