Daylight Saving Time: Java on z/OS SDK Products

URGENT - ACTIONS REQUIRED: Changes to Daylight Saving Time will affect IBM SDK on z/OS products downloaded from IBM developerWorks or ordered.

This information below describes the PTF required for each z/OS Java SDK product at a particular SDK Service Refresh (SR) level. There may be PTFs later than those listed, but any later PTF would contain the preceding DST support.

For detailed and definitive information about the DST content of each Service Refresh and the countries covered see:
DST updates in Service Refreshes of Java SDKs and JREs.

Service Refreshes of the SDK/JRE required

The strongly-recommended method to protect your systems is to upgrade them to the latest Java Service Refresh level, using the downloads from the IBM z/OS Java web site (this site) or ordering the PTF.

The following tables summarize the DST-enabled Java refreshes and their DST content. All Java fixes are cumulative. Therefore, the latest PTF contains all previous fixes.

Java 1.4.2

Product:
IBM SDK for z/OS, Java 2 Technology Edition, Version 1.4, 5655-I56

Java 5.0

Product:
IBM 31-bit SDK for z/OS, Java 2 Technology Edition, Version 5.0, 5655-N98

Java 6.0

Product:
IBM 31-bit SDK for z/OS, Java Technology Edition, Version 6.0, 5655-R31

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The IBM Time Zone Update Utility for Java

IBM is also making available the IBM Time Zone Update Utility for Java, to help customers apply the DST-related fixes to an installed SDK in unusual situations where upgrading to the recommended Service Refresh is not a practical option.

The IBM Time Zone Update Utility for Java provides an alternative, secondary mechanism for applying the DST changes to your Java systems. However, the strongly-recommended method to protect your systems is to upgrade them to the latest Java Service Refresh level, using the downloads from the IBM z/OS Java web site (this site) or ordering the PTF.

IBM understands that significant upgrades to installed systems may require substantial periods of planning and testing to minimize risks. We recognize that situations may arise where these risks are high and we are offering a mitigation in the form of a utility program for updating existing product bundles and installed binaries, including back-level service refreshes. This may be helpful in certain situations, for example:

• You need to apply the DST changes for Bermuda (and possibly other countries making late decisions to adjust their dates in step with the US) prior to the availability of IBM Service Refreshes that contain these fixes.
• You have recently applied an i-fix or unique patch to your installed Java system, and a version of the SDK/JRE containing the both this patch and the DST fixes is not available.
• Your environment contains non-IBM products that package or prereq the SDK/JRE and your supplier is unable to upgrade them to a level that supports a DST-enabled version of the SDK/JRE.
• You have multiple copies of the SDK/JRE installed and the Utility's "search and locate" capability would be useful, prior to upgrading your systems by applying Java Service Refreshes.

The IBM Time Zone Update Utility for Java contains two functions:

• searching your installation to detect and locate all the IBM-supplied Java SDKs/JREs on your systems. These may include SDKs/JREs installed as part of IBM products, SDKs/JREs installed stand-alone, supplied as part of operating system distributions or from IBM developerWorks, for example. For all instances discovered, it will report the JRE/SDK release/refresh level and identify the level of DST updating currently applied.
• locating the time zone information for each identified SDK/JRE and then modifying the package by replacing the current time zone data with the updated time zone data.

The Utility will upgrade the following release levels of SDKs on z/OS platforms: 1.4 and 5.0.

You can download the IBM Time Zone Update Utility for Java, at the URL here:
http://www.ibm.com/developerworks/java/jdk/dst/

Further information about the Utility is contained in the README, available at this URL.

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