z/OS system UTC time change notes - such as DST Daylight Saving Time changes

Document ID : KB000049278
Last Modified Date : 14/02/2018
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Description:

When set (or re-set) the system date/time value, that specifies the offset from UTC, you have to follow a specific procedure relating to CA Date Simulator.

Solution:

When you set (or re-set) the z/OS system date/time value, that specifies the offset from UTC, you have to act as follows:

  • First CLEAR all CA Date Simulator "sets"
  • Reset the system time
  • Then do the CA Date Simulator "sets" again

If this isn't done, CA Date Simulator "results" will be off by the new time offset from UTC - for example by one hour when changing back from the Daylight Saving Time to normal/winter time or vice versa.