Add Your Personal Calendar to OWA, Google, and TeamSnap Calendars

Office 365 Notification MC201582 published on January 17 announced that users could add personal calendars and TeamSnap accounts to OWA. This capability first surfaced in November 2019 when Microsoft tested it with selected accounts. This early testing was to validate the functionality prior to commencing deployment in production.

Deployment began to targeted release Office 365 tenants in January, was halted briefly to make some adjustments, and has now reached my tenant. Microsoft anticipates that deployment to standard release tenants will begin in April and worldwide availability will be achieved in July.

Update 4 May: Microsoft now says that the deployment will begin in mid-May and be finished in July 2020.

Just One Personal Calendar

A personal calendar means a calendar belonging to an or Google account. TeamSnap is a U.S.-based service to organize calendars for recreational clubs, such as soccer or hockey clubs.

To add a personal calendar, open OWA’s calendar module and select Add personal calendars (Figure 1) The use of the plural term here might lead you to believe that you can add multiple personal calendars. However, OWA currently limits users to choosing either an or Google calendar, and you can only add a single calendar of the chosen type.

OWA's Add Personal Calendar option
Figure 1: OWA’s Add Personal Calendar option

Shared Calendar Views

You’ll need to authenticate to open and add the selected calendar. I was already signed into my account, so OWA added it automatically instead of asking which account to use.

After OWA opens the calendar, it includes events from the personal calendar in its view. In Figure 2, you can see events from my work and personal calendar shown in the same view. This is like the way that events appear when you choose to display several work calendars, such as those belonging to delegated, shared, or group mailboxes.

Personal and work events shown in the OWA calendar
Figure 2: Personal and work events shown in the OWA calendar

You can create new events in the personal calendar from OWA. One slight problem I noted is that OWA displays “Calendar” twice in the new event screen (Figure 3). The work calendar is the top calendar while the personal calendar is below, but it’s not obvious at first glance.

Figure 3: Which calendar is which?

Microsoft says that the calendar selection issue will be alleviated when they ship a new calendar picker (soon, apparently).

You can’t add new TeamSnap events from OWA as access is limited to read-only. Also, calendars added by OWA are unavailable in Outlook desktop or Outlook mobile.


When you include a personal calendar in OWA, you can synchronize information from that calendar to Exchange Online to allow personal commitments to be included in their free/busy map. This means that when someone else tries to schedule a meeting with you using the Scheduling Assistant, your personal commitments are blocked out as busy.

If you don’t want to synchronize personal events to Exchange Online, toggle this option off in the Accounts section of Calendar options (Figure 4).

Toggling the synchronization of personal events to the OWA calendar
Figure 4: Toggling the synchronization of personal events to the OWA calendar

PowerShell Controls for Personal Calendars

Microsoft enables support for personal and TeamSnap calendars by default and there’s no obvious reason why you might want to disable these features, but you can with PowerShell. The features are controlled by the PersonalAccountCalendarsEnabled and TeamsnapCalendarsEnabled settings in the OWA mailbox policies assigned to mailboxes. To block access, update these settings to False. Here’s how to do it for all OWA mailbox policies in the organization:

Get-OWAMailboxPolicy | Set-OWAMailboxPolicy -PersonalAccountCalendarsEnabled $False -TeamsnapCalendarsEnabled $False

Like any change to OWA mailbox policies, the update won’t be effective until it is distributed across the tenants and clients refresh their settings. Updating the settings does nothing to remove access to personal or TeamSnap calendars from mailboxes where they are already configured.

Small but Good Change

Enabling access to personal calendars is an example of a feature that doesn’t seem important to tenant administrators while adding value to users. The demarcation between personal and work lives is increasingly blurred. Adding personal calendars to OWA reflects that fact and allows users to organize their time better, which is surely the reason to have calendars in the first place.

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One Reply to “Add Your Personal Calendar to OWA”

  1. Anyone else having issues with this lately? One day about 2 weeks ago it stopped working…message about “something went wrong” and when you try to reconnect or remove it takes you to the settings page for “Accounts” then continues to fail and says “…try again later.”

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