Change time zone settings

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

(iseries) Verify that extended National Language Support (NLS) is installed on the i5/OS server. If extended NLS support is not already installed, install it by selecting option 21 when you install the base operating system (5769-SS1).

Determine the scope at which to set the time zone value. We 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 the time zone setting, the HP-UX operating system 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 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.

In general cases, the time zone for application server is inherited from the time zone set for the operating system; Java should be inherit the time zone from the operating system, and the application server will use the time zone set for each Java Virtual Machine (JVM). If we need to configure a different time zone for a single JVM, we can set the TZ environment variable in the application server, modify the properties file, or specify a command-line parameter when the JVM starts.

(dist) We can use the TZ environment variable to set the time stamps for the application logs.

(zos) We can specify the Unix System Services (USS) TZ variable as an environment variable to set the time stamps for the application logs.

(iseries) We can change the time zone setting for the application logs for all of the processes running in a single application server, for all of the application servers running under a user profile, or for all of the JVM processes running on the WAS subsystem.

• Set the time zone for each of the server processes.

  1. In the 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 specified TZ in the Name field, and EST5EDT in the Value field, Eastern United States is used as the time zone setting for all of the server processes.

     (zos) The following table lists the Unix System Services (USS) TZ variable values for the various time zones in the United States. The same values can be specified for the WebSphere TZ variable.

     states time zones. This table lists the United States

     Time zone code	Time zone	CUT offset
     CUT0GDT	Coordinated Universal Time	CUT
     EST5EDT	Eastern United States	CUT-5
     CST6CDT	Central United States	CUT-6
     MST7MDT	Mountain United States	CUT-7
     PST8PDT	Pacific United States	CUT-8
     AST9ADT	Alaska	CUT-9
     HST10HDT	Hawaii	CUT-10

     See the topic Time zone codes for the TZ environment variable in the z/OS Information Center for a complete list of the Unix System Services (USS) TZ variable values.

  3. Click Apply, and then click Save to save the changes.

  4. Stop and restart all of the affected application server that were running when you made the time zone changes.

• (iseries) Update the user.timezone property with the appropriate time zone setting in the properties file.

  • To change the time zone setting for all application servers under one user profile, update the user.timezone property in the user profile properties file with the appropriate time zone setting.

  • To change the time zone setting for a WAS subsystem, update the user.timezone property in the properties file, or set a system local variable for that subsystem.

• 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

Results

Your new time zone setting are in affect for the designated servers.

Subtopics

• (iseries) Set the time zone for all of the application servers running under a user profile
  We can update the user.timezone property in the properties file for a user profile to set the time zone for all of the application servers running under that user profile. Setting this property ensures that all application components running under that profile use the same time zone.

• (iseries) Set the same time zone for all of the JVM processes
  We can set the same time zone for all of the JVM processes running on the IBM i server.

• Time zone IDs that can be specified for the user.timezone property
  The following table lists the time zone IDs that we can specify for the user.timezone property.

Related tasks

WebSphere variables