Changing time zone settings

In some application environments, it is important that application server components use the same time zone. You can use the administrative console or system environment variables to ensure that your application components use the correct time zone.

Before you begin

Note: If you plan to change the system clock, stop the application server first. After you stop the server, change the system clock, and then restart the server. If you change the system clock on one system, you must ensure the clocks on all systems that communicate with each other, and have the product installed, are synchronized. Otherwise, you might experience errors, such as security tokens no longer being valid.

Determine the scope at which you want to set the time zone value. You can set the time zone value such that is applies for an entire cell, for an entire node, or only for a specific server.

Remember that time zone IDs should include an offset and, in almost all cases, a daylight saving time zone name for consistent results. For example, specify EST5EDT for Eastern Standard Time, Daylight Savings Time.

When the East African Time Zone (EAT) is specified as your time zone setting, the HP-UX operating system Java™ virtual machine (JVM) uses Greenwich Mean Time (GMT). Therefore, log file time stamps are based on GMT instead of EAT. The situation might also causes problems in server federation if you attempt to synchronize with servers that are running on an operating system whose JVM correctly handles the EAT.

If you need to use East African Time Zone as the time zone setting for a specific function, instead of using the following procedure, add the -Duser.timezone=EAT parameter to the appropriate Java command. For example, to have an application server use EAT as its time zone setting, add the -Duser.timezone=EAT parameter to the startServer command.

• Set the time zone for each of your server processes.
  1. In the administrative console, click Servers > Server Types > WebSphere application servers > server_name > Java process management > Process definition > Environment entries.
  2. Set a value for the TZ variable.
     • If the TZ variable is included in the list of defined variables, click TZ, and then specify a new time zone value in the Value field.
     • If the TZ variable is not included in the list of defined variables, click New, and then specify TZ in the Name field, and the appropriate time zone value in the Value field.
     For example, if you specify TZ in the Name field, and EST5EDT in the Value field, Eastern United States is used as the time zone setting for all of your server processes.
  3. Click Apply, and then click Save to save your changes.
  4. Stop and restart all of the affected application server that were running when you made the time zone changes.
• Set the time zone with a command-line property for each JVM.
  For example, use the following parameter to set the time zone on the Java call:

  -Duser.timezone=time_zone_code