iCal 5.x: About iCloud calendars
If you have an iCloud account and Mac OS X 10.7.2 or later, you can use iCal to access and manage your iCloud calendars. In iCal, you can easily keep track of your meetings or appointments, view multiple calendars at the same time, expand your calendars to full screen, see when you’re more busy or less busy, and add subscribed calendars to your iCloud Calendar account so you can view them in iCal and in the Calendar app on devices with iOS 5 or later (without resubscribing to them).
You can also share iCloud calendars with friends and family members who also use iCloud. (You can give your friends and family members read-only or read-and-write privileges to the shared calendars.) If you don’t specify who you want to share a calendar with, the calendar is set as read-only and anyone with the calendar’s web address can subscribe to it.
To view your iCloud calendars on other devices and computers, set up your iCloud Calendar account on each device and computer. For more information about iCloud, visit the iCloud website.