The same system time zone should be set for both master and slave. Otherwise statements depending on the local time on the master are not replicated properly, such as statements that use the NOW() or FROM_UNIXTIME() functions. You can set the time zone in which MySQL server runs by using the --timezone=timezone_name option of the mysqld_safe script or by setting the TZ environment variable. See also Section 16.4.1.8, “Replication and System Functions”.

If the master is MySQL 4.1 or earlier, then both master and slave should also have the same default connection time zone setting; that is, the --default-time-zone parameter should have the same value for both master and slave.

CONVERT_TZ(...,...,@@session.time_zone) is properly replicated only if both master and slave are running MySQL 5.0.4 or newer.