Do I need to be concerned with time zones on the exchange servers in a lab?

Q: I am testing in a lab. Do I need to only be concerned with the Time Zones the Exchange Servers are in or the Time Zones of the Outlook Client? Since in the lab over half of the mailboxes come back with No Time Zone, what is the best way to find it out?
A: The concern is the time zone of the Outlook client. DST is tied to the time zone of the client. The time zone of the Exchange servers has no affect.