How do You sync iPhone calendars?
How do you sync calendars between an iPhone 6 IOS 8.4 and an iMac OS X 10.9.5? It was working. However, something changed and the calendars do not sync now.
iPhone 6, iOS 8.4, Trying to sync calendar with iMac
On the phone: Settings > iCloud > Calendars on
On the Mac: Apple menu > System Preferences > iCloud > Calendar on
If they were both already on, the following may help: Get help using iCloud Calendar - Apple Support