Staying Organized on the Move - iConnected: Use AirPlay, iCloud, Apps, and More to Bring Your Apple Devices Together - page 152

Figure 7-2
On an iOS device, enable iCloud calendar syncing in the Settings app.
The same principle for setting up Calendars for iCloud on an iOS device applies to iCloud syncing
on a Mac: iCloud needs to be running and the calendar syncing feature needs to be turned on. Then,
on your Mac.
1. Choose Apple > System Preferences to open the System Preferences application.
2. Go to the iCloud system preference.
3. Check that the iCloud account you want to use with Calendars is active (see Figure 7-3) and
that the Calendars & Reminders option is checked.