If you share calendars among friends, family members, and co-workers, you may have sometimes found yourself in the annoying situation of having their reminders go off on your iPhone. Fortunately, the iOS 8 Calendar app now allows you to turn off notifications on a per-calendar basis.
To do this, simply go into the Calendar app, tap the “Calendars” button in the bottom center to bring up your list of Calendars, and then tap the red “i” to the left of the calendar you’d like to change. Scrolling all the way to the bottom will reveal an “Event Alerts” option — simply toggle this OFF to prevent alarms in that calendar from showing up on the current device.
Note that this works not only for shared calendars, but even your own personal calendars, which can be useful if you have a calendar for which you might like to receive alerts on only specific devices; you can turn off alerts on your iPhone while still having them go off on your Mac or iPad, for instance.
Keep in mind that this will only silence actual calendar alarms; notifications you receive when somebody changes a shared calendar are controlled by the “Show Changes” setting which appears further up above the color settings. Controlling both options separately means that you can still see when somebody changes an appointment in their calendar while not having their alarms go off on your device..