When you create an all-day event in Appointment Entity, the end time is displayed as the day after the start time.
This only can be seen in Dynamics CRM Online 2016.
It did not happen in 2015 version. The start time and the end time showed exactly the same date and time.

I don’t see any point displaying the end time as the day after the start time, and there is no workaround.
The customer certainly is confused and I hope to see it fixed in the future release, please.

Product Version：since 2016