iCloud: Share calendars in iCloud

You can share a calendar privately or publicly using Calendar on iCloud.com.
Share a calendar privately
Click the Share button
to the right of the calendar name in the sidebar, then select Private Calendar.
Type the invitee’s email address in the Add Person field, then press Return.
Click the pop-up menu with the invitee’s name, then choose access privileges (View & Edit or View Only).
For each person you want to share the calendar with, repeat steps 2 and 3.
When you’ve invited everyone and set their privileges, click OK.
Invitation emails are sent from your iCloud email address to the participants you specified.
Share a calendar publicly
Click the Share button
to the right of the calendar you want to share, then select Public Calendar.
To invite people to view the calendar, click Email Link.
Type one or more email addresses in the To field, then click Send.
The people you specify automatically receive an invitation email that includes the calendar’s URL. An invitee doesn’t need to be an iCloud user to accept an invitation to view a shared public calendar.
You can resend invitations to one or more invited participants at any time.