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Shared calendars improvements in Outlook for Windows

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Hi, Office Insiders! My name is Julia Foran, and I’m a Program Manager on the Outlook team. I’m excited to share some great improvements we’ve made to shared calendars in Outlook for Windows. 

Improved shared calendars experience 

We have dramatically improved the reliability and sync latency for shared calendars and delegated calendars in Outlook across platforms. You might have already noticed some of these enhancements if you use Outlook for Mac, Outlook on the web, or Outlook Mobile. 

What has changed in shared calendars 

What kinds of improvements have we made? Here are some of the highlights. 

  • Instant sync of shared calendars: Previously, if changes were made to a shared calendar, it could take up to a few minutes for the shared calendar recipients to see the changes reflected in their view of the shared calendar. Now, changes sync and appear instantly.  
  • Accept a meeting without having to send an email response: If you select Accept > Do Not Send a Response, others can still see your response in the Tracking tab. Previously, the organizer and other attendees would not see your response if you did not explicitly choose to send one. (NOTE: This improvement also applies if you chose not to send a response when tentatively accepting or declining a meeting request.) 
  • Editing a meeting series end date will not reset past meeting details: Past meeting details won’t change nor will you see this message: If you changed specific appointments in the series, your changes will be discarded and those appointments will match the series again.” 
  • No more prompts about who to send an update to: If you edit a meeting or a meeting series, and you only change the list of attendees, you won’t need to choose whether to Send updates only to added or deleted attendees or Send updates to all attendees. Outlook figures it out for you, and will only send the update to added or deleted attendees. (NOTE: If the meeting contains a group or a distribution list from which one or more attendees were removed, the meeting update will be resent to those groups and distribution lists to ensure that the meeting remains on all the expected attendees’ calendars.) 

For a full list of improvements, check out this page. 

Known issues 

Your calendar must be upgraded and the improvements must be enabled in order for you to be able to try out these new capabilities. To check whether your calendar has been upgraded, and if not, how to manually upgrade it, click here. (NOTE: We have not finished upgrading all calendars automatically.) 

Turn on shared calendars improvements check box in Microsoft Exchange dialog box

Scenarios to try 

  • Create a new recurring series without an end date, change two of the series events to have unique titles, and then modify the series to add an end date. Notice that the unique titles remain and are not reset when you change the duration of the series! 
  • Clear and then select again one of your shared calendars in which the improvements are available. Notice how the events appear instantly, and there is no delay while events are loading! 
  • Ask the calendar owner to create an event on the shared calendar. Notice how you see that new event synced instantly in Outlook for Windows, and you see the changes immediately. 


This feature is available to Office 365 subscribers running Current Channel (Preview) Version 2103 (Build 13901.20148) or later. 

Features are released over some time to ensure things are working smoothly. We highlight features that you may not have because they’re slowly releasing to larger numbers of Insiders. Sometimes we remove elements to further improve them based on your feedback. Though this is rare, we also reserve the option to pull a feature entirely out of the product, even if you, as an Insider, have had the opportunity to try it. 


If you have any feedback or additional suggestions for improvements, please click Help > Feedback to let us know.

Learn what other information you should include in your feedback to ensure it’s actionable and reaches the right people. We’re excited to hear from you! 

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