I can say this thread
https://forums.macrumors.com/threads/521263/ answer #7
ConnectIT said this:
I followed the instructions in this link:
http://support.apple.com/kb/HT1692
Here are the specific steps that I followed:
Open iTunes.
From the Edit menu, choose Preferences.
Click the Syncing tab.
Click the Reset Sync History button.
If the issue continues and you know all of the data is on the iPhone or iPod touch:
Reset the Sync History again using the steps above.
Remove all of the contact and calendar information from Outlook. (I actually moved all of my contacts and appointments to another .pst folder, just to be on the safe side.)
Select the device in iTunes and click the Info tab.
Scroll down to the Advanced section and under "Replace information on this iPhone/iPod" make sure Contacts and Calendars are not selected.
Click Apply.
For Outlook 2007, follow these steps to disable third-party add-ins:
Open Outlook 2007
From the Tools menu, choose Trust Center.
Select Add-ins from the left column.
Look at the list of add-ins beneath "Active Application Add-Ins" and determine if anything is listed other than the "iTunes Outlook add-in." If so, continue on to disable those add-ins.
In the Manage box, click COM Add-Ins, and then click Go.
In the COM Add-Ins dialog, deselect the checkbox for each third-party add-in in this list.
Click OK.
I deselected ALL of the addins except the "iTunes Outlook Addin".
I have now tested it by creating, deleting, and editing Calendar appointments on both the PC and the iPhone and everything seems to be working fine in the Day/Week/Month views!
This seemed to help with my itunes at home it only syncs Apps, music, video and photos. I just did the reset the history in itunes and the sync took about a minute maybe less. Or it seemed like a minute compared to yesturday and the one at work.
