Changing agent timezone in oem 12c

/opt/app/oracle/agentHome/core/12.1.0.2.0/bin>echo $TZ
US/Pacific
/opt/app/oracle/agentHome/core/12.1.0.2.0/bin>./emctl stop agent
Oracle Enterprise Manager Cloud Control 12c Release 2
Copyright (c) 1996, 2012 Oracle Corporation.  All rights reserved.
Stopping agent ..... stopped.

/opt/app/oracle/agentHome/core/12.1.0.2.0/bin>./emctl resetTZ agent
Oracle Enterprise Manager Cloud Control 12c Release 2
Copyright (c) 1996, 2012 Oracle Corporation.  All rights reserved.
Updating /opt/app/oracle/agentHome/agent_inst/sysman/config/emd.properties...
Successfully updated /opt/app/oracle/agentHome/agent_inst/sysman/config/emd.properties.
Login as the em repository user and run the  script:
exec mgmt_target.set_agent_tzrgn('xxx:3872','US/Pacific')
and commit the changes
This can be done for example by logging into sqlplus and doing
SQL> exec mgmt_target.set_agent_tzrgn('xxx:3872','US/Pacific')
SQL> commit
/opt/app/oracle/agentHome/core/12.1.0.2.0/bin>./emctl start agent