Is this element mandatory when sending "GetUserAvailabilityResponse" to exchange server? If no, when should this element be sent?
Reference: https://msdn.microsoft.com/en-us/library/office/aa563496(v=exchg.150).aspx https://msdn.microsoft.com/en-us/library/office/aa565001(v=exchg.150).aspx
Is this element mandatory when sending "GetUserAvailabilityResponse" to exchange server? If no, when should this element be sent?
GetUserAvailabilityResponse is the response that the Exchange Server will return in response to GetUserAvailabilityRequest https://msdn.microsoft.com/en-us/library/office/aa563800(v=exchg.150).aspx
So its unclear as to what your question is as you would never send this yourself (the timezone is however a critical part of the request), workhours should be returned in the response if it has been set but you can't control whether it is or isn't returned.
