> My calendar display changed unexpectedly and now shows recurring
> events as running for two days.
You have a mismatch in the daylight saving time settings between Outlook and
Windows. In Outlook, click Tools>Options>Calendar Options>Time Zone. Make
sure the time zone is correct and that the "Adjust for daylight saving time"
is checked or not, as appropriate for your time zone. Then, double-click
the clock in the system tray, select the TIme Zone tab and do the same
thing.

Signature
Brian Tillman