我的理解是没有什么大的风险，只要保证应用的时区和数据库的时区一样就可以。

当然如果说有风险的话，也就是因为他们之间不一样，可能会容易导致误操作。比如说集群里面装了多套数据库，那么就要注意每套数据库的时区设置，管理起来就要多注意这种具体的要求，不要忘记了保持应用和数据库的一致。

Understanding Time Zone Settings on Cluster Nodes
Oracle RAC requires that all cluster nodes have the same time zone setting.

During an Oracle Grid Infrastructure for a cluster installation, the installation process determines the time zone setting of the Grid installation owner on the node where Oracle Universal Installer (OUI) runs. OUI uses that time zone value on all of the nodes as the default time zone setting for all processes that Oracle Clusterware manages. This default setting is used for databases, Oracle ASM, and any other managed processes. However, if you start an instance with SQL*Plus, you must ensure that the time zone value that Oracle RAC uses is the same as the Oracle Clusterware time zone. You can change the time zone that Oracle Clusterware uses for a database by running the command srvctl setenv database -env 'TZ=time zone’

Understanding Time Zone Settings on Cluster Nodes