The OWA and Windows Outlook does not, they show the proper time (MST) so no issues there. So although this UTC issue gets created only when appointments are created by iPhone apps, even then the only one that shows the UTC time is the Mac Outlook 2016. If I only had Outlook for Windows, or just use the Calendar on the Mac, I would not be aware of this glitch at all. The issue is the Mac Outlook 2016 program issue.