When advanced features are enabled you will see logs in /var/log/sys.log like the following for each advanced feature node as the node is starting up. The timezone specified in the log seems to indicate the wrong timezone but the Africa/Abidjan timezone is the equivalent of UTC time. So as long as your appliance is supposed to be configured with UTC then the timezone Africa/Abidjan is actually correct. In a future release the log content may change to show the actual UTC offset, which would be 0, to clarify a bit more what Africa/Abidjan corresponds to.

<14>Jul 26 21:30:55 logapp llqn application="logu" eventTime="2019-07-26T21:30:55.658Z" systemId="" nodeId="querynode" sourceNodeId="" targetNodeId="" type="INFO" tenant="" sourceIP="" targetIP="" actor="akka://Logu/user/ZKConfigurationManager" logger="com.tibco.apollo.container.configuration.ZKConfigurationManagerActor" sourceUser="" targetUser="" id="" msg="Setting timezone to "Africa/Abidjan""