Assume that you have a room mailbox that has the BookingWindowInDays parameter set in a Microsoft Exchange 2013 environment that has cumulative update 9 or cumulative update 10 applied. When you schedule a meeting for the room mailbox outside the value boundary of the BookingWindowInDays parameter, you can't receive an "Accept" or "Decline" response from the room mailbox. Additionally, the availability of the room mailbox calendar is still displayed as "Tentative" during the period of the meeting.
This issue occurs because the EndTime attribute of the room mailbox is smaller than the StartTime attribute in the GetRecurringCalendarItems function call.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
Article ID: 3100519 - Last Review: Dec 15, 2015 - Revision: 1
Microsoft Exchange Server 2013 Enterprise, Microsoft Exchange Server 2013 Standard Edition