Office 365 default Calendar's ID changes automatically

Question

I was using V2 DLL of Office 365 API for performing calendar operations. I am saving default calendar\'s ID for performing operations on it.

It was working fine for me f

Answer 1

I am circling back with the team on this one. The Id of a folder should never change. It is based on the PR_ENTRYID of the folder in store which is immutable within a mailbox. I am not sure what extra goodness they stuff in the id in REST - it does appear there is some concatenation going on.

As for change key, it isn't related directly to the id, so there really isn't a way to convert from the change key to the id. This appears to simply be a bug on our side. But of course, the change key changes whenever there is a change to the folder and is an opaque blob (even to us at the OData and EWS layer).

Of interest, you could also request the PR_ENTRYID extended property with your fetches and you should see that the underlying id is always the same. But that wouldn't fix anything other than to future your understanding of what is going on under the covers.

I will post back when I get a response from them.