Why Calendar Entries Are Duplicated in Outlook [Solved]

Anuraag | June 25th, 2020 | How to, Outlook

“Yesterday night while looking at my Outlook calendar, I have seen that several of my appointments and meetings are suddenly showing up multiple times. Even some of the calendar entries are more than five times. It does not make any sense at all and it won’t allow me to delete the duplicates calendar entries. So, I start searching for a solution to delete duplicate calendar entries but I am unable to find any reliable solution. So, if anyone knows how to remove duplicate calendar entries from Outlook then please help me”

Date duplicate like emails, contacts, calendar entries is the most common issues in Microsoft Outlook and this can happen due to various reasons. So if you want to get rid of duplicate calendar entries from your Outlook, then stay with us. Here in this write-up, we are going to discuss how to remove duplicate calendar entries in Outlook. But before starting the blog let’s see what are the reasons behind why calendar entries are duplicated in Outlook?

Reasons for Duplicate Calendar Entries in Outlook

As we said above there are various reasons that are responsible for creating duplicate calendar entries in Outlook. The major ones are mentioned below:

  • Syncing the Outlook profile with the mobile or other application that does not support Outlook recursion pattern. Leads to create multiple calendar entries in Microsoft Outlook.
  • If the Outlook Rules do not configure properly in Outlook profile, then you will encounter duplicate calendar entries in Outlook.
  • If the allow duplicate to be created option is enabled during the migrating calendar item from another application to Outlook.
  • Third-party anti-virus can intercept your Outlook profile that can lead to duplicate calendar entries in Outlook. 

Quick and Effective Way to Remove Duplicate Calendar Entries in Outlook

The above-mentioned reasons are the most common and major reasons for creating duplication in Outlook. So to delete duplicate calendar entries in Outlook first you have to identify the duplicate calendar entries one by one. After that, you can delete it manually from your Outlook.

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One-by-one method makes the manual method a very time-consuming process. Along with that, it is not beneficial in the case of numerous calendar entries are saved in your Outlook calendar. Thus, to make this task easy go for a professional recommended solution and i.e., SysTools Outlook Duplicate Remover. It is a tool that is capable to remove duplicate calendar entries in Outlook 2016, 2013, 2010, and all its below versions in a very effective manner.

Here are the working steps of the tool

Step 1: Install and launch Outlook duplicate remover on your Windows machine

Step 2: Click on the Add Files or Add Folders option to select the PST file

Step 3: Now, choose the Calendar checkbox provided in the Categories section

Step 4: Click on the Specify Duplicate Criteria to customize the duplicate removal process

Step 5: Choose the action that you want to apply on duplicate calendar entries

Step 6: Click on the Next button to start the process of deleting duplicate calendar entries in Outlook.

Remove Duplicate Calendar Entries in Outlook – Manually

To delete duplicate appointment or calendar entries in Microsoft Outlook manually, please do as follow

Step 1: First, open Microsoft Outlook on your Windows machine

Step 2: Now click on the file option>>Change View>> List option

Step 3: After that click on view setting button.

Step 4: Click on the short button from advanced view settings popup

Step 5: Click on the box below sort item by subject, then by location then by start >> OK

Step 6: Now compare adjacent appointments to select multiple calendar entries. Now, hold the ctrl key and then press the delete button to remove them.

You Might be Interested in: Why Do I Receive Duplicate Emails in Outlook?

Why this Solution?

  • This Outlook duplicate remover tool comes with some advanced features that will ensure no data and alternation of folder hierarchy during the process.
  • It has a facility to remove duplicate Outlook items from PST/OST/BSK files too
  • Including duplicate calendar, this duplicate Outlook email remover tool has an ability to remove emails contacts task journal and notes too
  • It will also give you the option to remove duplicate from password protected Outlook PST, OST, and BAK files.


Outlook data duplication can happen in any version of Outlook and create lots of performance issues like lower productivity, unnecessary storage space issue, and many more. Therefore, in this write up we have discussed the best and most secure manual as well as an automated way to remove duplicate calendar entries in Outlook.