Mark,
So our issue is we were running on 5.9 and migrated to 6.0 now
Our appointment object has 10 rules on Create/Edit which solve the AM and PM time issue - So it has several Rules which must fire in order to result in the required Timestamp for the Calander API.
Anyways, what I am saying is ours is broken now somehow and I think there could be a correlation to the Appointment Object and the issues you & I have.
a) Does your object also have rules which are manipulating the timestamp?
b) Is it an Appointment object?
Thanks!