If you receive an email notice that you have been granted access to share another person's calendar, you can accept or reject the share.
When you accept the share, the shared calendar displays in your Calendar list.
Click Accept Share in the email. The Accept Share dialog opens and describes the role granted to you.
Before you accept you can customize the calendar name and select a color for messages to be displayed.
Check the Send mail about this share, to send a confirmation back to the Grantor. (optional)
Click Yes. The new shared calendar is added to your Calendar list. The message is moved to your Trash folder.