DB Control Not Starting due to Incorrect Timezone

Cause

The Agent does not start because of incorrect time zone.

Solution

1. check ORACLE_HOME/sysman/admin/supportedtzs.lst and ORACLE_HOME/sysman/admin/nsupportedtzs.lst for a correct value on TZ
2. Comment the line AgentTZRegion="<some value>" in
   ORACLE_HOME/<hostname>_<SID>/sysman/config/emd.properties
3. export TZ=<chosen time zone from step 1>
4. emctl config agent getTZ
5. emctl config agent updateTZ
6. emctl start dbconsole

Note: on 11.1 and higher DB Console, it is enough to run "emctl resettz agent" and then follow the instructions in the output (ie. running th mgmt_target.set_agent_tzrgn procedure) to change or set the correct timezone on the DB Console.