Last reviewed on September 2, 2014   —  9 Comments

Microsoft Outlook comes with a file named Outlook.hol (Outlook.txt in Outlook 2000 and older) that includes lists of holidays that you can import into your personal Calendar folder using the Tools | Options | Calendar (or Calendar Options) | Add Holidays command. This makes it easy to add holidays and many users wind up importing the same group of holidays twice.

You can remove the duplicates one of two ways: delete all events in the Holiday category then re-add the holidays you want added or use the Created date field to sort by date added an delete the duplicates, which added at the same time.

You can use the Sort by Created date method to remove any duplicated calendar items.

Delete the Holiday category

In Outlook 2007 and Outlook 2003: switch to the By Category view.
In Outlook 2010 and 2013: switch to a List view then arrange by Category.

Select the Holiday category then press Delete.

Go to Options, Calendar and click Add Holidays. Select the Locations you want to install and complete the wizard.

Sort by Created date

In Outlook 2010 and Outlook 2013:

  1. Switch to the View ribbon and select Change View, List
  2. Click View Settings then Columns
  3. Select Created and click Add -> to add it to the view
  4. Click OK to return to Outlook
  5. Sort by the Created date field
  6. The holidays that are imported together will have the same Created date
  7. Select the first event and hold Shift as you select the last
  8. Press Delete

To remove the duplicates from Outlook 2007 and older

To use the Created date method to delete duplicated appointments in Outlook 2007 and older, follow the instructions below.

  1. Choose View | Current View | Events to switch to the table-format Events view. All the holidays will be listed under the Recurrence: (none) group. (Outlook 2003: View | Arrange By | Current View | Events)
  2. Right-click any column heading, then choose Field Chooser.
  3. In the Field Chooser, switch from the Frequently-used fields list to Date/Time fields, and then drag the Created date to the view to add it to the fields displayed.
  4. Click on the Created column header to sort by that field.
  5. You should now see two distinct sets of holidays, each in reverse chronological order. Click on the first holiday of the set you want to delete.
  6. Use the scroll bar to view the last holiday of that set. Hold down the Shift key as you click on the last holiday. This selects all the holidays in that set.
  7. Press Delete to remove them all from the Calendar folder.
  8. Drag the Created column header out of the view to remove it.

While its very easy to remove duplicate Holidays and a duplicate removal utility is not necessary, if you have duplicates of other calendar appointments, one of the tools below can remove the duplicates.


Tools in the Spotlight

Deduper - Outlook Duplicate Remover

Deduper does exactly as the name suggests, it searches and removes all duplicates - including appointments, contacts, notes, tasks or emails.

Duplicate Appointments Eliminator

The Duplicate Appointments Eliminator allows you to either delete all the duplicates or move them to a folder of your choice. Comparisons of two appointments (optionally) based on subject, location, start time, end time, body, categories, recurrences, and required attendees. Works with Exchange public folders or other shared folders and you can choose to operate on a single folder or select many folders at once. Works with Microsoft Outlook 2007, Outlook 2003, Outlook 2002 and Outlook 2000. Enter code WD9BHK53 during checkout.

Duplicate Killer

Outlook duplicate remover add-in for Microsoft Outlook to find and remove duplicate contacts, emails, calendar items, tasks and notes automatically. Remove Outlook duplicates. Merge Outlook contacts and other items. Compare, assign category, flag and move duplicates to selected folders. Preview duplicate search results prior to processing. Duplicate Killer has Junk Contacts removal functionality, regarding contacts that have too little information. Duplicate Killer is compatible with the latest Windows 8 and Outlook 2013.

Duplicates Remover for Outlook

Delete duplicate contacts, notes, tasks, journal and calendar items in Microsoft Outlook folders and Exchange Server folders. Duplicates can be marked, copied or moved to any folder. It supports searching across the folders. Supports all versions of Outlook, including Outlook 2007/2010. Version 2.6


1-Click Duplicate Delete

1-click solution to remove duplicate mails, contacts or calendar items. Merges contacts automatically, has an undo function and a configurable advanced mode. Version 3.03 Now supports Outlook 2010 (both 32 and 64 bit).

Accurate Outlook Duplicate Remover

Accurate Outlook Duplicate Remover (AODR) can find and remove all duplicate Outlook items automatically. It quickly removes duplicates from Contacts, Calendar, Tasks, Notes and Email folders in one click. You can select any folder for duplicate Removing. It helps you to use your Outlook much more efficiently. Free.

Delete Duplicates for Outlook

Delete Duplicates for Outlook deletes duplicate e-mails. Detect and remove duplicate messages, contacts, calendar items, tasks, journal entries and notes. Compare messages by content (Standard), by part of the content (Special) or by unique message-id's (Light). Compare attachments and/or embedded files, by name and/or by content. Compare duplicates across several mailboxes or in within the boundaries of individual mailboxes. Use Regular Expressions. Works with all Outlook versions, inc. Outlook 2010/2013 32 or 64-bit.

Kernel for Outlook Duplicates

Find the duplicates email items of Outlook Mailbox and easily remove, mark or flag them. You can also move duplicate items into subfolder and control on the unnecessary growth of pst file.

NoMoreDupes for Outlook

NoMoreDupes detects and removes all duplicated Outlook items both in an Outlook pst file, a public folder or in an Exchange account. It shows the found duplicates in a preview for the user to decide which duplicates to remove. You can move the duplicated Outlook items to your "Deleted Items" or to any other folder you specify. NoMoreDupes uses a special algorithm to detect the Outlook duplicates. This Outlook-Add-In works with all versions of Outlook, including Outlook 2010/2013 64bit.

Outlook Duplicate Items Remover

Free tool for removing duplicate items from Outlook folders. ODIR recognizes duplicates in Contacts; Calendar; Tasks; Notes and Email folders. Using ODIR is very easy: select a folder and click the button Remove Duplicate Items. ODIR scans the selected folder for duplicates and MOVES all duplicates found to a subfolder ODIR_duplicate_items. Version 1.2

Outlook Duplicate Remover

Outlook Duplicate Remover allows you to find and remove Outlook duplicates and junk contacts in one click. Search duplicate items and merge Outlook duplicates automatically. Remove Outlook duplicates, such as duplicate Email, duplicate Contacts and Calendar events and Junk contacts. It is an automatic software add-in for Microsoft Outlook without any settings to configure. Duplicate Remover is compatible with latest Windows 8 and Outlook 2013 (including Outlook "Click-to-Run" versions) as well as Outlook 2010, 2007, 2003, 2002 and Exchange Server Public Folders. Supports French and German languages.

Outlook Duplicates Remover

Removes duplicate items from Calendar, Tasks, Contacts, Notes, and mail folders. Free.

Stellar Phoenix Duplicate Remover

Clean up your Outlook mailbox from unwanted and duplicate emails with Outlook duplicate remover tool. This software works as an Add-Ins in Outlook and removes duplicates as per different time span and scan criteria. Customized operations like Mark as Expired or Flag, Delete Permanently, Copy to folder and more are also a notable feature of this software.


  1. Pete Chamberlain says


    Have just used your information to add new dates to outlook 2007 and remove duplicates (forgot to uncheck UK when adding my wifes country of origin holidays).

    Thank you for your easy to read and use instructions


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