Initial time zone setting

During the initial startup, the operating system sets the initial time zone.

There is no shipped default value for the time zone (QTIMZON) system value. The time zone (QTIMZON) system value can be set in iSeries™ Navigator and from the IPL Options display during an attended initial program load (IPL).

To determine the initial value for the time zone (QTIMZON) system value, the operating system performs the following actions:

Attempts to retrieve time zone from the QWCTIMZON data area
During the IPL of an i5/OS™ software upgrade, the operating system will look for a data area named QWCTIMZON in the QSYS library. To create the data area before installation, see Set the time zone before upgrading. If the data area is found, the following steps are taken:
1. Attempts to find a time zone description object whose name matches the time zone description object named in the data area. If this step fails, proceed to 1.b.
2. Attempts to find a time zone description object whose name is derived from the offset specified in the data area. This name will consist of the letter Q, followed by an N if the offset is negative or a P if the offset is positive, followed by the offset hours and minutes, and finally by the letters UTCS. For example, if the offset specified in the data area is -06:00, the operating system will attempt to find a time zone description named QN0600UTCS. Note that if the offset is zero, the character representing the sign ('N' or 'P') will be omitted, and the name used is Q0000UTC. If this step fails, proceed to 1.c.
3. Attempts to create a new time zone description whose name and offset match the information specified in the data area. This time zone description does not support DST. For example, if the data area specified is -05:15MYTIMEZONE, the operating system will attempt to create a time zone description named MYTIMEZONE with an offset of negative five hours and 15 minutes. If this step fails, proceed to 2.
Attempts to retrieve time zone from the offset from UTC (QUTCOFFSET) system value
If the data area QWCTIMZON does not exist, or the preceding steps fail, the operating system will attempt to use the value specified in the offset from UTC (QUTCOFFSET) system value. The following steps are performed:
1. Attempts to find a time zone description object whose name is derived from the offset specified in the offset from UTC (QUTCOFFSET) system value. See 1.b for information about how this name is derived. If this step fails, proceed to 2.b.
2. Attempts to create a new time zone description whose name was derived in the previous step 2.a and whose offset matches the information specified in the offset from UTC (QUTCOFFSET) system value. This time zone description will not support daylight saving time.

If all of the preceding steps fail, the time zone (QTIMZON) system value will not be set. In iSeries Navigator, the time zone field is blank, and in the character-based interface, the time zone parameter is set to *N (not available). In addition, the offset from coordinated universal time (UTC) is set to 0. Then, the system's local system time is set to the current coordinated universal time (UTC).