Editing WoW:API GetGameTime (section)

=== Addendum ===
A wiki user added "difference between two clients can exceed a minute [disregarding hours]" to the general server time API description above, but its unclear if they meant for users on different zone server or not, since the same zone server will have the same server "hours" for all clients. The preceding commentary above explains the split-server cases.

The reason the times may only flip to the next minute between two clients only approximately at the same time, is that the server wont send an update every time the API is called, as this is a client-side only call and always returns immediately. Instead, the client caches the last server time is received, and the client flips the minute on its own based on client time even if the server hasn't sent any messages that would carry server time by the time the minute would need to flip for the client. This is also one of the reasons that server time is only in minutes, with no seconds.