IT29180: Adjust schedule time for daylight savings

APAR status

• Closed as program error.

Error description

• An IBM MQ Managed File Transfer scheduled transfer is set up to
  run at 01:00 AM every day.  On the day of the daylight saving
  change (where the clocks move forward one hour). the time for
  the next scheduled transfer was changed to 00:00 AM. However,
  the time should have been changed to 02:00 AM.
  

Local fix

Problem summary

• ****************************************************************
  USERS AFFECTED:
  This issue affects users of IBM MQ Managed File Transfer (MFT)
  who have scheduled transfers that:
  
  - Run every day (ie. the scheduled transfer was created with the
  -oi parameter set to days)
  - And use a time base of SOURCE (ie. the scheduled transfer was
  created with the -tb parameter set to SOURCE).
  
  
  Platforms affected:
  MultiPlatform
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  To understand the problem, consider the following scenario:
  
  In the United Kingdom, daylight saving time in 2019:
  
  - Began at 01:00AM  on Sunday, 31st March
  - Ended at 02:00AM on Sunday, 27th October
  	
  A scheduled transfer was set up to run at 01:00AM every day. The
  scheduled transfer was configured with the -oi parameter set to
  "days", and the -tb parameter set to SOURCE.
  
  On the 30th of March, 2019, the scheduled transfer ran as
  expected at 01:00AM.
  
  On the 31st of March, daylight saving started and the clocks
  moved forward one hour. However, the scheduled transfer actually
  ran at 00:00AM on that day. From this point onwards, the
  scheduled transfer always ran at 00:00AM	
  
  IBM MQ Managed File Transfer agents used the
  java.util.Calender.add() method to compute the next time that a
  managed transfer should run. If this method calculated a time
  that did not exist on the specified day, due to daylight saving,
  then it would move that time back an hour.
  
  For example, adding one day to 01:00AM on the 30th of March
  would have resulted in the time 01:00AM on the 31st of March.
  However, that time did not exist on the 31st of March in the
  United Kingdom (due to daylight saving, the clocks went from
  00:59AM to 02:00AM on this day). As a result, a time of 00:00AM
  on the 31st of March was returned.
  

Problem conclusion

• To resolve this issue, a new internal method has been created to
  adjust the time scheduled transfers will run. If a scheduled
  transfer was been configured with:
  
  - The -oi parameter set to "days",
  - And the -tb parameter set to SOURCE.
  
  then this new method will add 24 hours to the next schedule
  time. This allows the schedule time to:
  
  - Move forward one hour when the clocks move forward by an hour.
  - And move backwards one hour when the clocks go back by an
  hour.
  
  For example, if a scheduled transfer is configured to run at
  01:00AM every day, then with the new behaviour the scheduled
  transfer will run at:
  
  - 01:00 AM on the 30th of March 2019.
  - 02:00 AM on the 31st of March 2019.
  - 02:00 AM on the 1st of April.
  
  - 02:00 AM on the 26th of October.
  - 01:00 AM on the 27th of October.
  - 01:00 AM on the 28th of October.
  
  
  To enable this behaviour for an agent, add the entry:
  
  adjustScheduleTimeForDaylightSaving=true
  
  to the agent.properties file for that agent. The agent will need
  to be restarted for the change to take effect.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v8.0       8.0.0.14
  v9.0 LTS   9.0.0.9
  v9.1 CD    9.1.5
  v9.1 LTS   9.1.0.5
  
  The latest available MQ maintenance can be obtained from
  'WebSphere MQ Recommended Fixes'
  http://www-1.ibm.com/support/docview.wss?rs=171&uid=swg27006037
  
  If the maintenance level is not yet available information on
  its planned availability can be found in 'WebSphere MQ
  Planned Maintenance Release Dates'
  http://www-1.ibm.com/support/docview.wss?rs=171&uid=swg27006309
  ---------------------------------------------------------------
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Fix information

• Fixed component name

  IBM MQ MFT V8.0

• Fixed component ID

  5724H7252

Applicable component levels