Date iCal now supports iCalcreator v2.22+.

README.txt

@@ -16,10 +16,10 @@ Date iCal has several required dependencies, and an optional one:
 - The Feeds module is optional. It's needed only if you you wish to import iCal
   feeds from other sites.
 
-To install the iCalcreator library, download the project's v2.20.2 zip file:
-https://github.com/iCalcreator/iCalcreator/archive/e3dbec2cb3bb91a8bde989e467567ae8831a4026.zip
-Extract it, and copy iCalcreator.class.php to a folder in your Drupal site
-named sites/all/libraries/iCalcreator (you'll need to create that folder).
+To install the iCalcreator library, download the latest release from ths url:
+https://github.com/iCalcreator/iCalcreator/archive/master.zip
+Extract it, and copy the contents to a folder in your Drupal site named
+sites/all/libraries/iCalcreator (you'll need to create that folder).
 
 Or, if you have drush, you can install iCalcreator by running this command from
 your site's root directory:
@@ -243,6 +243,5 @@ The libraries/windowsZones.json file, which Date iCal uses to map Windows-style
 timezone names to real timezone IDs, is from Version24 of the Unicode CLDR:
 http://cldr.unicode.org/.
 
-The author of iCalcreator made backwards incompatible changes to the library
-in the v2.22 release. Thus Date iCal does not currently support any version of
-iCalcreator after v2.20.2.
+For some time, Date iCal did not support the 2.22+ of the iCalcreator library.
+This has been corrected, and any version should now function normally.

date_ical.make

@@ -2,6 +2,6 @@ core = 7.x
 api = 2
 
 libraries[iCalcreator][download][type] = "get"
-libraries[iCalcreator][download][url] = "https://github.com/iCalcreator/iCalcreator/archive/e3dbec2cb3bb91a8bde989e467567ae8831a4026.zip"
+libraries[iCalcreator][download][url] = "https://github.com/iCalcreator/iCalcreator/archive/master.zip"
 libraries[iCalcreator][directory_name] = "iCalcreator"
 libraries[iCalcreator][destination] = "libraries"

date_ical.module

@@ -165,13 +165,18 @@ function date_ical_libraries_info() {
     'name' => 'iCalcreator',
     'vendor url' => 'http://github.com/iCalcreator/iCalcreator',
     'download url' => 'http://github.com/iCalcreator/iCalcreator',
-    'version arguments' => array(
-      'file' => 'iCalcreator.class.php',
-      'pattern' => "/define.*?ICALCREATOR_VERSION.*?([\d\.]+)/",
-      'lines' => 100,
-    ),
-    'files' => array(
-      'php' => array('iCalcreator.class.php'),
+    'version callback' => '_date_ical_detect_icalcreator_version',
+    'versions' => array(
+      '2.20' => array(
+        'files' => array(
+          'php' => array('iCalcreator.class.php'),
+        ),
+      ),
+      '2.22+' => array(
+        'files' => array(
+          'php' => array('iCalcreator.php'),
+        ),
+      ),
     ),
   );
 
@@ -492,3 +497,16 @@ function _date_ical_convert_rrule_for_icalcreator($rrule) {
   }
   return $new_rrule;
 }
+
+function _date_ical_detect_icalcreator_version() {
+  $path = libraries_get_path('iCalcreator');
+  if (file_exists(DRUPAL_ROOT . "/$path/iCalcreator.class.php")) {
+    return '2.20';
+  }
+  else if (file_exists(DRUPAL_ROOT . "/$path//iCalcreator.php")) {
+    return '2.22+';
+  }
+  else {
+    return FALSE;
+  }
+}