By default, when you add an entry to your Outlook calendar, anyone viewing it will only be able to see the times you've booked out, but no details as to the booking itself.
Your manager may request that you share your Outlook calendar, so they can see what you've booked in each slot.
To do this, first open your calendar in Outlook, and then click Share Calendar in the ribbon.
Click on your calendar. You will see the following window. From here, you can see the permissions that other users have. In this instance, the whole organisation can view the details on the calendar. To change this, click 'My Organisation', then 'Can View All Details', and then click OK.
