After you share the calendar with other people, you can change the view permission with the steps below, if you think the person should have a higher or lower level:
Step 1: Click the "Calendar" button from the taskbar;
Step 2: Click the "Home" tab from the ribbon;
Step 3: Click "Calendar Permissions";
Step 4: In the "Calendar Properties" window, click the person's name and choose one of the reading levels.
– Free/Busy time: Time will be shown as "Free", "Busy", "Tentative", "Working Elsewhere", or "Out of Office";
– Free/Busy time, subject, location: Includes the availability and subjects of calendar items only:
– Full details: Includes the availability and full details of calendar items.
Step 4: Click "OK" to close the "Calendar Properties" window.