diff --git a/calendar/base/src/calEvent.js b/calendar/base/src/calEvent.js
index 935c603dde56..4cedc95ace06 100644
--- a/calendar/base/src/calEvent.js
+++ b/calendar/base/src/calEvent.js
@@ -1,5 +1,7 @@
 function calEvent() {
     this.wrappedJSObject = this;
+    this.initItemBase();
+    this.initEvent();
 }
 
 calEvent.prototype = {
@@ -10,13 +12,18 @@ calEvent.prototype = {
             !aIID.equals(Components.interfaces.calIItemBase) &&
             !aIID.equals(Components.interfaces.calIEvent))
         {
-            dump ("calEvent QI failed to " + aIID + "\n");
             throw Components.results.NS_ERROR_NO_INTERFACE;
         }
 
         return this;
     },
 
+    initEvent: function () {
+        this.mStartDate = createCalDateTime();
+        this.mEndDate = createCalDateTime();
+        this.mStampDate = createCalDateTime();
+    },
+
     clone: function () {
         var m = new calEvent();
         this.cloneItemBaseInto(m);
diff --git a/calendar/base/src/calEvent.js.pre b/calendar/base/src/calEvent.js.pre
index b3fcf20132e8..19ef83b73b7a 100644
--- a/calendar/base/src/calEvent.js.pre
+++ b/calendar/base/src/calEvent.js.pre
@@ -45,6 +45,8 @@
 //
 function calEvent() {
     this.wrappedJSObject = this;
+    this.initItemBase();
+    this.initEvent();
 }
 
 calEvent.prototype = {
@@ -55,13 +57,18 @@ calEvent.prototype = {
             !aIID.equals(Components.interfaces.calIItemBase) &&
             !aIID.equals(Components.interfaces.calIEvent))
         {
-            dump ("calEvent QI failed to " + aIID + "\n");
             throw Components.results.NS_ERROR_NO_INTERFACE;
         }
 
         return this;
     },
 
+    initEvent: function () {
+        this.mStartDate = createCalDateTime();
+        this.mEndDate = createCalDateTime();
+        this.mStampDate = createCalDateTime();
+    },
+
     clone: function () {
         var m = new calEvent();
         this.cloneItemBaseInto(m);
diff --git a/calendar/base/src/calItemBase.js b/calendar/base/src/calItemBase.js
index e1cfd4c229ca..2a0f6ed47ec1 100644
--- a/calendar/base/src/calItemBase.js
+++ b/calendar/base/src/calItemBase.js
@@ -30,6 +30,18 @@ calItemBase.prototype = {
     },
 
 
+    initItemBase: function () {
+        this.mCreationDate = createCalDateTime();
+        this.mAlarmTime = createCalDateTime();
+
+
+        this.mRecurrenceInfo = null;
+        this.mAttachments = null;
+        this.mContacts = null;
+        this.mProperties = null;
+    },
+
+
 
     cloneItemBaseInto: function (m) {
         m.mImmutable = false;
@@ -107,3 +119,14 @@ calItemOccurrence.prototype = {
     next: null,
     previous: null
 };
+
+
+
+
+
+function createCalDateTime() {
+    const kCdtClass = Components.classes["@mozilla.org/calendar/datetime;1"];
+    const kCdtInterface = Components.interfaces.calIDateTime;
+
+    return kCdtClass.createInstance(kCdtInterface);
+}
diff --git a/calendar/base/src/calItemBase.js.pre b/calendar/base/src/calItemBase.js.pre
index 2e201ebc3fc4..453684193a84 100644
--- a/calendar/base/src/calItemBase.js.pre
+++ b/calendar/base/src/calItemBase.js.pre
@@ -71,6 +71,18 @@ calItemBase.prototype = {
         this.mImmutable = true;
     },
 
+    // initialize this class's members
+    initItemBase: function () {
+        this.mCreationDate = createCalDateTime();
+        this.mAlarmTime = createCalDateTime();
+
+        // fix me
+        this.mRecurrenceInfo = null;
+        this.mAttachments = null;
+        this.mContacts = null;
+        this.mProperties = null;
+    },
+
     // for subclasses to use; copies the ItemBase's values
     // into m
     cloneItemBaseInto: function (m) {
@@ -149,3 +161,14 @@ calItemOccurrence.prototype = {
     next: null,
     previous: null
 };
+
+//
+// helper functions
+//
+
+function createCalDateTime() {
+    const kCdtClass = Components.classes["@mozilla.org/calendar/datetime;1"];
+    const kCdtInterface = Components.interfaces.calIDateTime;
+
+    return kCdtClass.createInstance(kCdtInterface);
+}