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Connect Microsoft 365

  • Sign in with Microsoft (OAuth)

This guide covers all Microsoft calendar services: Outlook.com (personal Microsoft accounts @outlook.com, @hotmail.com, @live.com), Microsoft 365 (work or school accounts), Office 365 (business subscriptions) and Exchange Online (enterprise email and calendars).

Steps

  1. Go to Calendar Connections

    From your SyncMyDay dashboard, navigate to Calendars in the main menu, or go directly to the Calendar Connections page.

    Calendar Connections page with provider options (opens the full-size image)
    Calendar Connections page with provider options

  2. Click “Microsoft 365”

    Find and click the Microsoft 365 button with the Microsoft logo.

    Microsoft 365 button on Calendar Connections page (opens the full-size image)
    Microsoft 365 button on Calendar Connections page

  3. Sign in with Microsoft

    You'll be redirected to Microsoft's secure sign-in page. Enter your Microsoft email address:

    • Personal: @outlook.com, @hotmail.com, @live.com
    • Work/School: Your organization's email (e.g., you@company.com)
    Microsoft Sign-In screen (opens the full-size image)
    Microsoft Sign-In screen

  4. Enter your password

    After entering your email, you'll be prompted for your password. Enter your Microsoft account password.

    If you have multi-factor authentication (MFA) enabled, you'll need to approve the sign-in on your phone or authenticator app.

  5. Grant permissions

    Microsoft will show a permissions screen asking if you want to let SyncMyDay access your calendar. Click Accept to continue.

    • Read your calendars — to detect when you have events scheduled
    • Create and modify calendar events — to create blocker events
    • Delete calendar events — to remove blocker events when needed
    • Maintain access to data — for continuous synchronization
    Microsoft permissions consent screen (opens the full-size image)
    Microsoft permissions consent screen

  6. Select calendars to sync

    After granting permissions, you'll return to SyncMyDay where you can select which Microsoft calendars you want to use for syncing.

    Most accounts will have at least:

    • Calendar — your main calendar
    • Birthdays — contact birthdays (you can skip this)

    You may also see:

    • Shared team calendars
    • Resource calendars (meeting rooms, equipment)
    • Calendars shared with you by colleagues
    Calendar selection dialog from Microsoft account (opens the full-size image)
    Calendar selection dialog from Microsoft account

  7. Connection complete

    Your Microsoft 365 calendar is now connected and ready to use. You'll see it in your Calendar Connections list with an Active status.

    Connected calendars list with Microsoft 365 showing Active status (opens the full-size image)
    Connected calendars list with Microsoft 365 showing Active status

Common issues

“Your organization needs to approve this app”

Why this happens: Your IT department has restricted which apps can access company data.

Solution:

  1. Contact your IT administrator or help desk.
  2. Ask them to approve “SyncMyDay” in the Microsoft 365 admin center.
  3. Or request an exception for your account.

This is common in larger organizations and is a security best practice.

Connection shows “Error” status

Common causes:

  • Your password was changed.
  • Multi-factor authentication settings changed.
  • Organization revoked access.

Solution: Click the Refresh button to re-authenticate, or disconnect and reconnect the calendar.

Can't see a shared calendar

Shared calendars should appear if they're added to your Outlook. If missing:

  1. Make sure the calendar is visible in Outlook web or app.
  2. Disconnect and reconnect your Microsoft account.
  3. Ensure you have at least “Can view all details” permission.

Next steps

Connect another calendar A sync rule needs at least 2 calendars. Open Create your first rule Choose where busy time comes from and where it goes, and add filters. Open

Technical details

For developers and IT

Microsoft Graph API

SyncMyDay uses the Microsoft Graph API with these permissions:

  • Calendars.ReadWrite — read and write calendar events
  • offline_access — maintain access when the user is offline

OAuth 2.0 authentication

We use the standard OAuth 2.0 authorization code flow:

  • Supports both personal Microsoft accounts and Azure AD accounts.
  • Tokens are refreshed automatically every 60 minutes.
  • Refresh tokens are valid for 90 days (automatically renewed).

Real-time synchronization

Microsoft Graph change notifications (webhooks) enable instant sync:

  • Subscriptions are created for each connected calendar.
  • Notifications are received within 2–3 minutes of changes.
  • Subscriptions are renewed every 3 days automatically.
  • Fallback polling occurs every 15 minutes if webhooks fail.

Enterprise admin consent

IT administrators can pre-approve SyncMyDay for all users:

  1. Go to Azure AD Portal → Enterprise Applications.
  2. Search for “SyncMyDay” or add it via App ID.
  3. Grant admin consent for the organization.
  4. Users can then connect without approval prompts.

API throttling

Microsoft Graph has the following limits:

  • Per app: 10,000 requests per 10 minutes
  • Per user: 2,000 requests per second

SyncMyDay's webhook-based architecture minimizes API calls and stays well within limits.

Data residency

Your calendar data remains in Microsoft's data centers. SyncMyDay only stores:

  • Calendar IDs and names
  • Event start/end times (no titles or descriptions)
  • Encrypted OAuth tokens

Didn't work? Write to us and we will help you.