Currently the start time and end time of an appointment item is returned in UTC. This is fine. However it is currently not possible to determine in which time zone the user originally placed the appointment.
Assume the user is currently located in Copenhagen (UTC+1) and creates and appointment taking place at 10.00 UTC-7. In add-in code I can get the start time as UTC (17.00) and I can most likely also determine in which time zone the user is currently located and/or which time zone the user's calendar is by default using. However, I would like to be able to determine that the user originally created the appointment in UTC-7.
If the user creates a recurring appointment it IS possible to get the timezone of the appointment through the recurrence data. I like to be able to determine the same for a non-recurring appointment.