How to share an Outlook calendar and set permissions

To share the calendar open Outlook and click on Calendar and the Home tab.  Then click Share Calendar and then Calendar again as shown:

The Calendar Properties box will pop up; on the Permissions tab click the Add button to add the user who you want to give access to your calendar:

In the Permissions section underneath, select the type of access you want the other user to have.   If the user wants to grant full access for another user to be able to manage their calendar, the Delegate option will need to be selected.

Click OK and this will send an email to the person you are sharing the calendar with.  The other user will receive an email inviting them to view the calendar – they need to click the Accept button in the top corner:

Finally, close Outlook down and re-start it for the changes to take effect.