Incorrect Timezone Returned from Graph API

Hello Shaina Rosenthal,

I understand you're seeing a mismatch where the user's time zone appears to be set correctly to UTC -5 (Eastern Standard Time), but the Microsoft Graph API still returns Central Standard Time when calling:

GET https://graph.microsoft.com/v1.0/me/mailboxSettings/timezone

This happens because the API reflects only the time zone stored in the user's Exchange Online mailbox settings. It doesn’t automatically sync with what's configured in Outlook, Windows, or Entra ID.

To check or fix this, the user can go to Outlook on the web, open Settings → General → Language and time, and review the time zone setting.

If it’s not set to Eastern Standard Time, it can be adjusted there directly.

Alternatively, you can update it via Graph API with this request:

PATCH https://graph.microsoft.com/v1.0/me/mailboxSettings
{
  "timeZone": "Eastern Standard Time"
}

Once updated, the API will return the correct time zone.

GET https://graph.microsoft.com/v1.0/me/mailboxSettings/timezone

For more details, you can refer to the official documentation:
Update user mailbox settings - Microsoft Graph

Hope this helps.

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If you have any other questions or are still experiencing issues, feel free to ask in the "comments" section, and I'd be happy to help.