Log in to Outlook.com in your browser, and go to your Calendar view.
Click on the gear icon in the top right-hand corner of the screen.
A panel will appear from the right. Click on “View all Outlook settings”, which you can find at the bottom.
In the window that appears, click on Calendar » Shared calendars. In the “Publish a calendar” section, select your calendar, and under Permissions choose “Can view all details”.