As an Outlook user, you can share your calendar with your colleagues so that they can view your calendar next to theirs. You can even allow them to edit your calendar and update any appointments you may have.

In Outlook, switch to the calendar view by clicking on the calendar icon.
At the top of the page, select Share, and choose the calendar you want to share.
Note: You can’t share calendars owned by other people.
Enter the name or email address of the person with whom you want to share your calendar.
Choose how you want this person to use your calendar:
‘Can view all details’ lets the person see all the details of your events.
‘Can edit’ lets the person edit your calendar.
Select Share.

If someone shares their calendar with you, click Accept when you see the invite.

You can now toggle on/off the calendar to view it alongside yours.