PK30359: SPECIFIC USE OF EST/MST IS AFFECTED BY CHANGES TO TIME ZONE RULES IN JAVA 1.4.2 SR5 AND BEYOND.

APAR status

• Closed as fixed if next.

Error description

• Timezone rules have been updated in IBM JDK 1.4.2 SR5 to support
  the new Daylight Saving Time (DST) dates for the US starting
  from year 2007. For further information on this see:
  http://v06dbl07.hursley.ibm.com/hursley/hiujava.nsf/pages/JavaDS
  Tinfo
  
  The timezone rules are obtained from the Olson Timezone database
  maintained at a public domain site. As part of the new timezone
  rules, a few other changes have been made, for example:
  
  1. In the eastern part of the US, the state of Indiana does not
  observe DST, while the rest of the eastern part of US does
  observe DST. Timezone ID EST (Eastern Standard Time) supports
  this geographic area and, timezone ID EST5EDT refers to the rest
  of the Eastern US that observes DST. This means that EST shows
  GMT-5:00 (as it doesn't support DST) throughout the year, while
  EST5EDT switches between GMT-4:00 and GMT-5:00 due to DST.
  
  2. Similarly, the timezone id MST (Mountain Standard Time)
  doesn't observe DST, so it would show GMT-7:00 throughout the
  year. The timezone id MST7MDT switches between GMT-6:00 and
  GMT-7:00 due to DST. This is because DST is not observed in most
  of the state of Arizona.
  
  Previous versions of the JDK (until 1.4.2 SR4) incorrectly
  accounted for DST in the EST and MST timezone IDs. Users should
  take care in understanding this change in behavior for these
  timezones.
  
  The US DST changes for year 2007 and beyond together with the
  above mentioned changes are available as part of IBM JDK 1.4.2
  SR5. Any Java based application, which uses the EST or MST
  timezone id (or hard-coded to use EST or MST timezone id) will
  be affected due to the change in behaviour, when the JDK is
  upgraded to 1.4.2 SR5 or beyond. If the application needs to
  consider DST, then EST5EDT and MST7MDT should be used
  respectively for Eastern and Mountain regions of US instead of
  EST and MST.
  

Local fix

• Use EST5EDT or MST7MDT in place of EST or MST.
  

Problem summary

• 1.4.2 SR5 Onwards, EST will be a timezone id representing
  Eastern TimeZone without daylight savings timeEST5EDT will be a
  timezone id representing Eastern TimeZone with daylight savings
  timeMST will be a timezone id representing Mountain TimeZone
  without daylight savings timeMST7MDT will be a timezone id
  representing Mountain TimeZone with daylight savings time.
  

Problem conclusion

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

Applicable component levels

• R42A PSY

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