Using New Outlook on Windows for professional communication and productivity
I have the same issue as a POP3/.pst user. I have found a work-around for those who are able to successfully integrate Outlook mail/contact/calendar entries with their iOS devices.
Open the calendar entry you wish to edit on an iOS device and use that device to make the time/date change. Hit "Done" on the iOS device. Close, then re-open Outlook and maybe, if you are fortunate, the change will be reflected in Outlook on your PC.