Geographically-dispersed organizations may determine that organizing their domain hierarchy by functional groups causes a domain to span more than one time zone. It is strongly recommended that you do not have domains that span multiple time zones. If you do need to configure a domain across time zones, be aware that a replica's time is taken from the master server, so the database updates will be synchronized properly, using Greenwich mean time (GMT). This may cause problems if the replica machine is used for other services that are time critical. To make domains across time zones work, the replica's /etc/TIMEZONE file has to be set locally to the master server's time zone when you are installing NIS+. After the replica is running, some time-critical programs may run properly and some may not, depending on whether these programs use universal or local time.