When you mark time as "out of office" on your calendar, your coworkers see it when they attempt to schedule a meeting with you. But wouldn't it be great if you could alert everyone at once in advance of your time away without affecting their free/busy status or cluttering their calendars? You can do this by setting your information to appear on their calendars as an all-day event, but unlike a normal all-day event, which usually is set to "busy," this all-day event is displayed as free time. Your coworkers' free/busy availability is not affected.
In Calendar, on the Home tab, click New Meeting.
Type a description in the Title box, , and if desired, enter a location in the Location box.
In the Teams Meeting group click the Red X Dont Host Online option so this is not a Teams Meeting
In the Start time and End time lists, select the start and end time for your time away from the office. For vacations, this usually involves full days. If this is the case, select the All day event check box.
Under Response Options make sure Request Responses is unticked.
In the options group Click on the Show As Dropdown and select Free
Add everyone you wish to alert to the Required line
Click on the Send button to complete.
If you have not entered a location select Send Anyway