Office 365 Working Hours for Resource Mailboxes

For various features to work correctly, such as the Custom room reservation on the Meeting Room display, you may be required to adjust your work hours and Timezone for your Resource Mailbox.

The PowerShell options you're looking for are listed here: Get-MailboxCalendarConfiguration

• Workdays: Days that appear in the calendar as work days in Outlook on the web
• WorkingHoursStartTime: Time that the calendar work day starts
• WorkingHoursEndTime: Time that the calendar work day ends
• WorkingHoursTimeZone: Time zone set on the mailbox for the working hours start and end times

Alternatively, if you sign into Outlook Web Access as your Resource Mailbox, you can adjust it there.

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Updated on: 08/01/2025