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If you are making changes to your iPhone calendar and after syncing the changes are not updated on your Microsoft Outlook calendar, I would recommend the information and steps located in the attached article.
Have a great day,
The above article is a Windows article. Pay no attention to the section from the article below, that redirects you support for Apple computers.
Important: If you are syncing with OS X Mountain Lion or earlier, see these articles instead:
The rest of the article is troubleshooting support and steps for Windows.