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Microsoft Calendar Integration (Plus)

WhenToMeet Plus integrates seamlessly with Microsoft Outlook calendars, including personal Outlook accounts, work Microsoft 365 accounts, and Hotmail calendars. This allows you to view your Microsoft calendar events and prevent double-booking across all your calendar platforms.

Note: Microsoft Calendar integration is a Plus feature. Upgrade to access Microsoft calendars.

What it does (and doesn't) do

  • Calendar Overlay: Shows your existing Microsoft calendar events as colored blocks on the scheduling interface
  • Availability Aggregation: Automatically blocks times when you're busy in your Microsoft calendar
  • Cross-Platform Integration: Works alongside Google Calendar for complete availability checking
  • Output Calendar: Choose to save new events to your Microsoft calendar
  • Real-time Updates: Calendar events refresh every 30 seconds to stay current
  • Does not "sync" events between calendars; your existing events stay where they are

Supported Microsoft Account Types

  • Personal Microsoft Accounts: Outlook.com, Hotmail, Live accounts
  • Microsoft 365 Business: Work and school accounts
  • Microsoft 365 Personal: Home and family subscriptions
  • Exchange Online: Enterprise email accounts

Set up

  1. Go to Settings → Calendar
  2. Click Connect Microsoft Calendar and complete the OAuth flow
  3. Sign in with your Microsoft credentials
  4. Grant calendar permissions when prompted
  5. Enable Calendar Overlay: Toggle "Show calendar overlay" in the scheduling interface
  6. Select Input Calendars: Choose which calendars to use for availability checking
  7. Choose Output Calendar: Select which calendar receives new events (can be Microsoft or Google)

Tip: You can connect both Google and Microsoft calendars for comprehensive availability checking.

Required Permissions

WhenToMeet requests the following Microsoft Graph permissions:

  • Calendars.ReadWrite: Read and create calendar events
  • User.Read: Access basic profile information
  • offline_access: Maintain connection without re-authentication

These permissions are necessary for calendar integration and conflict detection.

Calendar Overlay

  • Visual Integration: Your Microsoft calendar events appear as colored blocks alongside Google events
  • Color Coding: Microsoft events are displayed with distinct colors for easy identification
  • Real-time Updates: Events refresh every 30 seconds to show the latest information
  • Conflict Prevention: See all your commitments across platforms at a glance

Availability Aggregation

  • Microsoft calendars work seamlessly with Google calendars for availability checking
  • If you're busy in either Microsoft or Google calendars, that time is blocked
  • You can mix and match calendars from different providers (up to 8 total)
  • Custom availability rules still apply on top of calendar busy times

Output Calendar Selection

  • Choose any connected calendar (Microsoft or Google) as your output destination
  • Microsoft calendars appear alongside Google calendars in the selection dropdown
  • Events are created in the calendar you specify for each booking page
  • You can set different output calendars for different booking pages

Multiple Microsoft Accounts

  • Connect multiple Microsoft accounts (personal + work)
  • Each account can have multiple calendars
  • Mix personal Outlook.com with work Microsoft 365 accounts
  • All connected Microsoft calendars appear in your availability settings

Troubleshooting

  • "Connection failed" error: Ensure you're using the correct Microsoft credentials and that your account has calendar access.
  • "Upgrade required" message: Microsoft Calendar is a Plus feature. Upgrade your account to access this integration.
  • Calendar overlay not showing: Make sure you've enabled "Show calendar overlay" and selected your Microsoft calendars for availability checking.
  • Permissions error: Try disconnecting and reconnecting your Microsoft account from Settings → Calendar.
  • Events not updating: Events refresh every 30 seconds. If they're still not current, try refreshing the page or clicking "Refresh" on the connection.
  • "Already connected" error: You've linked this Microsoft account before. Manage existing connections in Settings → Calendar.

Privacy and Security

  • WhenToMeet uses Microsoft's secure OAuth 2.0 authentication
  • We only access calendar data, not emails or other personal information
  • Your calendar data is processed securely and not stored permanently
  • You can revoke access at any time through Microsoft's account settings or WhenToMeet settings

Mobile Experience

Microsoft Calendar integration works seamlessly on mobile devices. For the best experience, consider adding WhenToMeet to your home screen for quick access to your calendar settings and booking pages.

Enterprise Considerations

  • Works with Microsoft 365 Business and Enterprise accounts
  • Respects organizational calendar sharing policies
  • Compatible with Exchange Online and on-premises Exchange (via Microsoft Graph)
  • Ask your IT administrator if you encounter connection issues with work accounts

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