calendargoogle-calendariosiphone
I have my Google Calendar synced up to my iPhone 4S and by all the settings I can find, it looks like I am supposed to recieve alerts 15 minutes before every event. However, this has never happened.
How come there is no alert being displayed when an event is upcoming? I can see it in Notification Centre, but there is no banner or alert.
No, you can't disable pop-up reminders globally. You can turn off an alert by accessing the event properties in the Calendar app, but then it will be disabled in Google Agenda too.
This is different on iOS 8.
As described on iPad Academy, the option is located in Settings → Notifications → Calendar → Shared Calendar Changes.
Best Answer
Something that seems to work for Google calendars: on your phone, go to Settings => Mail, Contacts, Calendars. Scroll down to the Calendars block. Select Default alert times. You can then chose phone alerts by type of event.