Apple - how to force sync of calendars on iPhone?
In iOS 7 and later:
- Open Calendar app
- Click Calendars
- Drag down to refresh
EDIT: This has been fixed in recent versions of iOS. Please see @LukeWilliams answer which describes simply pulling to refresh the calendars in the Calendars list.
For deprecated versions of iOS: As of iOS 5 there is no super easy/obvious way to do this. What I have found that works, is opening Settings > Mail, Contacts, and Calendars > Tapping the email account you'd like to refresh > turn the calendar off > wait while it deletes it > turn the calendar back on.
sometimes by forcing a New Event, it triggers syncing.
On iOS 6 or earlier, my experience is that the easiest way to sync the calendars is, from within the Calendar App on the iPhone, tap the Calendar Button in the upper left corner. You now have a display with a grey Edit button in the upper left, A blue Done button in the upper right, and down at the bottom on the left is a white clockwise circular arrow. Tap it and it will sync the calendars.