I've been struggling with calendar issues far too long so I finally created a support ticket. It is confirmed there is a major problem with calendar with iOS and EAS. Try creating an appointment starting on Date 1 at 2 PM going to another date DATE 2 at 11 AM using Windows 10, Microsoft Outlook, or any client other than iOS using EAS. Now look at your calendar in iOS such as an iPhone or iPad and you'll see your appointments likely start or stop on the wrong date and/or show ALL DAY vs. appointment times.
This is beyond critical. I've already double booked one overnight stay in my travels from suffering from this unreliable calendar system. BEWARE of your appointments!
ST has had years to get EAS working properly. Don't dare blame this on flaky EAS or iOS, this is purely an implementation issue. If this is all done via hacking like it seems had to be done to figure out MAPI, what is the likelihood MAPI is going to work on par with Exchange?
I've already gotten quotes from Dell and CDW for Exchange licenses. I'm hoping ST can quickly fix this issue but this product simply cannot be trusted for business OR personal use. ST developers should have working over the weekend to correct this critical bug that could affect all iOS users and I'm sure there are plenty.
Now the question is why didn't they see this problem before I did? Why can't they create an appointment from EAS and then see how popular clients show this test? Testing continues to be an epic failure with ST and I've been here for years and cannot believe they rely on the community as the test system instead of their own logical tests such as if existed would have clearly identified this bug long before I did.
Not going to trust MAPI, can't trust EAS which is not new. Very very sad from a long time customer.