Auto attendant intermittently routes call to out of region/not in dial plan UM server

Question

Hi all,
Exchange 2013 on prem, hardware not virtual. CU5 w/Lync 2013 
I've got calls that get intermittently routed to UM servers that are out of region and not in the dial plan.  The out of region UM server sees the call is outside of business hours & sends helpdesk calls to voicemail instead of the appropriate phone
menu.
Additionally, when Exchange admins who are in different time zones look at the GUI w/the AA's business hours they see a time skew even though the time displayed is listed as Eastern.  I think the mis-routing & the time zone skew are related.  When
the Tokyo server gets the call it checks the time: 3AM? Not in business hours even though in Eastern Time where the call is supposed to go, it is in business hours.
In the Lync client log (as seen via the snooper tool) this is the last message before the call gets transferred:
“ms-diagnostics:
15032;reason="Re-directing request to the destination in 302” 
Additionally the time zone on the AA schedule is set to Eastern Time.  Why is the TYO UM server ignoring this and applying local time? 
Any tips to point me in the right direction would be appreciated.
Adam

Answer 1

Number two was correct!  The affected site did not have an arbitration mailbox.  Details follow.
I still have the underlying problem of AA's getting the time zone of the UM server applied rather than the time zone they are allegedly set to (for example Beijing business hours served from a TYO UM server getting TYO time).
With the help of MS support we resolved the immediate problem: calls getting routed to our TYO site.
It turns out that every AD site with Exchange servers needs to have an arbitration mailbox with the grammar generator role set & ready.  If a site with UM servers does not have an arbitration mailbox it will proxy the call to another site that does.
 In our case, it would route them to our Tokyo site that applied the wrong hours to the auto attendant.
Here's how we created the arbitration mailbox
[PS] C:\temp\autoattendant>New-Mailbox -Arbitration -Name "A new UM Grammar Mailbox" -Database <some db hosted in site> -UserPrincip
alName [email protected] -DisplayName "A new UM Grammar Mailbox"
C:\temp\autoattendant>Set-Mailbox [email protected] -Arbitration -UMGrammar:$true
This keeps the call from going out of site to an Exchange UM server in a different time zone.
The tricky bit is that this does not immediately work.  The mailbox needs to pick up the OrganizationCapabilityUMGrammarReady capability which it will only get when the grammar generator runs.  In 2010 you were able to kick this off manually.  In
2013 it runs once a day.  You have to wait until Get-Mailbox -Arbitration | fl name, servername, persistedcapabilities shows the OrganizationCapabilityUMGrammarReady has been assigned to the mailbox.
I still have not yet resolved the underlying problem of why UM servers are ignoring the time zone setting on AA's business hours.