{Normal Chaos}

For those of you who use Outlook as your primary (or even, secondary) scheduling tools, you have probably experience issues with Outlook having duplicate events. This is especially problematic if you synchronize your Outlook calendar across multiple devices. In a perfect world, those devices would identify the duplicates and merge them. Reality, however, is significantly different.

The following Outlook macro (and instructions) will assist you in removing duplicate events. This macro will not merge events if they are slightly different, but it simply checks to see if two events are EXACTLY the same, and it removes one of them.

Instructions
1. From Outlook, open your macro editor. (Either press alt-F11 or select Tools, Macro, Visual Basic Editor.)
2. In the macro editor window, select Insert, Module. This will create a text editor window into which you can paste the macro.
3. In the text editor window, paste in the code below. (I recommend you review the code to be sure it's doing what you want.)
4. You can run the code by placing your cursor anywhere in the code window between the "Sub" and "End Sub" statements and pressing F5. Optionally, you can close the Visual Basic window, then select Tools, Macro, Macros..., and "Run" RemoveDuplicateEvents.

The last section of the macro removes all items from your Deleted Items folder. I discovered this is important, because events in my Deleted Items folder "mysteriously" kept re-duplicating. Once I cleaned out the folder, my sync'ing was successful.

Here is the code for the macro. Hopefully, it is useful to someone. Please let me know if you have any problems so I can correct make an effort to correct the macro.

IMPORTANT A regular copy/paste should work correctly. However, you may experience issues with line breaks that prevent the macro from working. If this is the case, the Outlook VB editor will make it abundantly clear what lines are invalid, so it should be pretty easy to fix rogue line wrapping.

':::::::::::::::::: Macro Begins Here; Copy this line and everything below
Sub RemoveDuplicateEvents()
    Dim olApp As Outlook.Application
    Dim olAppointment1 As Outlook.AppointmentItem
    Dim olAppointment2 As Outlook.AppointmentItem
    Dim olItems As Outlook.Items
    Dim olDeletedItems As Outlook.Items
    Dim olNS As Outlook.NameSpace
    Dim SkipConfirmation As Boolean

    Set olApp = New Outlook.Application
    Set olNS = olApp.GetNamespace("MAPI")
    Set olItems = olNS.GetDefaultFolder(olFolderCalendar).Items
    Set olDeletedItems = olNS.GetDefaultFolder(olFolderDeletedItems).Items

    olItems.Sort ("Subject")
    olItems.Sort ("Start")
    Dim DeleteCount As Integer
    Dim z As Integer
    Dim FreeBusyStatus As Boolean
    DeleteCount = 0

    FreeBusyStatus = MsgBox("Do you want to set the status for all-day events to 'Free'?", vbYesNo, "Set Free Busy Status") = vbYes
    If FreeBusyStatus Then
        SkipConfirmation = Not MsgBox("Do you want to be prompted to set free times for all-day events?", vbYesNo, "Skip Confirmation?") = vbYes
    End If

    For z = olItems.Count To 2 Step -1

             Set olAppointment1 = olItems.Item(z)
             Set olAppointment2 = olItems.Item(z - 1)
             Debug.Print olAppointment1.Subject & vbCrLf & olAppointment2.Subject
             DoEvents

             With olAppointment1
                 If .Subject = olAppointment2.Subject And _
                         .Start = olAppointment2.Start Then
                     .Delete
                     Debug.Print "Calendar item " & Left(olAppointment2.Subject, 25) & "..." & " deleted"
                     DeleteCount = DeleteCount + 1
                 End If
             End With
             With olAppointment2
                 If .AllDayEvent And .BusyStatus <> olFree And FreeBusyStatus Then
                     If Not SkipConfirmation Then
                         If MsgBox("Do you want to set """ & .Subject & """ as free time?", vbYesNo, "Confirm Status Change") = vbYes Then
                             .BusyStatus = olFree
                             .Save
                             Debug.Print .Subject & " updated!"
                         End If
                     Else
                         .BusyStatus = olFree
                         .Save
                         Debug.Print .Subject & " updated!"
                     End If
                 End If
             End With
    Next
    If MsgBox(DeleteCount & " duplicate Outlook calendar items have been removed." & _
        vbCrLf & "Do you want to clear your deleted items folder?" & vbCrLf & _
        "(This must be done to prevent re-syncing 'deleted' entries)", vbYesNo, "Confirm Deleted Items Removal") = vbYes Then
        ' Clear deleted items folder
        For z = olDeletedItems.Count To 1 Step -1
            olDeletedItems.Item(z).Delete
            DoEvents
        Next
    End If
    MsgBox "Cleanup Complete!", vbOKOnly, "End of Processing"

End Sub

':::::::::::::::::: Macro Ends Here

* This macro was developed using Outlook 2003. It works very well for me, but I make no guarantee it will work for you. Please review the code before running to be sure it doesn't perform some task you are not expecting. Also, I strongly recommend backing up your Outlook data (usually a PST file) before running the macro.

Please leave feedback letting me know whether or not it works for you. If you have problems with it, please let me know that as well.