diff --git a/src/Type/WellKnownResponseObjectType.php b/src/Type/WellKnownResponseObjectType.php
index fc6ed521e..737af12a2 100644
--- a/src/Type/WellKnownResponseObjectType.php
+++ b/src/Type/WellKnownResponseObjectType.php
@@ -12,5 +12,26 @@
  */
 abstract class WellKnownResponseObjectType extends ResponseObjectType
 {
+	/**
+     * Represents the proposed end time of a meeting.
+     *
+     * @since Exchange 2013
+     *
+     * @var string
+     *
+     * @todo Make a DateTime object.
+     */
+    public $ProposedEnd;
+	
+	/**
+     * Represents the proposed start time of a meeting.
+     *
+     * @since Exchange 2013
+     *
+     * @var string
+     *
+     * @todo Make a DateTime object.
+     */
+    public $ProposedStart;
 
 }