diff --git a/timeago.install b/timeago.install
index 42f07a9eb3f9f9f58337a4939720c578296899d0..a187d5cbabbd02d7c8b04cc53d494cd711b7eb06 100644
--- a/timeago.install
+++ b/timeago.install
@@ -15,6 +15,13 @@ if (!defined('TIMEAGO_LIBRARY_DOWNLOAD_URL')) {
 }
 
 /**
+ * Implements hook_install().
+ */ 
+function timeago_install() {
+  variable_set('date_format_time_ago_dynamic', TIMEAGO_FORMAT_MEDIUM_US);
+}
+
+/**
  * Implements hook_requirements().
  */
 function timeago_requirements($phase) {
@@ -146,6 +153,7 @@ function timeago_uninstall() {
     'timeago_js_strings_year',
     'timeago_js_strings_years',
     'timeago_js_strings_word_separator',
+    'date_format_time_ago_dynamic',
   );
 
   foreach ($variables as $variable) {
diff --git a/timeago.module b/timeago.module
index 585c47b273e85a630d3d0a3da629b6aa433a3c47..32a289a51e3913ad6dc79c052272a19742993f13 100644
--- a/timeago.module
+++ b/timeago.module
@@ -291,6 +291,15 @@ function timeago_date_formats() {
 }
 
 /**
+ * Implements hook_date_format_types().
+ */
+function timeago_date_format_types() {
+   return array(
+    'time_ago_dynamic' => t('Time ago (dynamically updating)'), 
+  );
+}
+
+/**
  * Implements hook_init().
  */
 function timeago_init() {