Outlook currenly uses 12 AM to 12 PM for All Day Events. This creates problem when it is for different time zone.

It would be useful to use additional time zone feature in outlook to display local time zone without changing time of operating system. Either you can change all day event to local time zone setting.

One best option to handle with this problem is storing all time zone using UTC(Universal Cordinated Time) so that there is no need for any other time settings and appointment can be rendered using local time zone.