Calendar will no longer sync with iPhone

Question

My calendar would sync with no problems and now it won't update the information on my iphone so I am stuck with the old information and having to manually update the calendar.
Please help.
Using version 6.0 of calendar
Using version 10.7 of iTunes
Using 6.0.1 on iPhone
Using OS X 10.8.2
Everything says it's up to date.  When I attempt to sync, nothing changes on the calendar.
Thank you,
Amy

Answer 1

Have you run scanpst.exe? That file is in the Microsoft Office folder. That does a scan of your Outlook.pst file and can help fix problems. Can you remember what you were doing when the problem began. Many times recurring appointments with open end dates can cause problems. Another thing that Outlook/Apple do not like too well are the way you set a reminder in an appointment. If you have an appointment with a reminder that is set to zero in Outlook, it can confuse the Apple calendar. Another thing to check is in iTunes, and that is resetting the sync history.
Also, you should not have to re-enter years of data, since the iPhone by default only syncs the last 30 days worth of data. Your archive generally is just resident on the computer. Once data goes to archive, it is removed from the phone due to the time period.
Try creating a new calendar in Outlook and put a couple of dummy appointments in it. Connect the iPhone to iTunes and set iTunes to sync all calendars. See if this new calendar syncs. If it does, you can import all of your old calendar data as Lawrence states to the new calendar and make that your default calendar by deleting the old one.
See if any of these steps helps.