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Daylight Saving Time (DST) 2007 information for IBM HTTP Server
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| | | Abstract | | Information about how changes to Daylight Saving Time (DST) in 2007 affect IBM HTTP Server. | | | | | | Content |  
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A provision of the United States Energy Policy Act of 2005 extends DST by four weeks, beginning in 2007. Several countries (Canada, Bermuda) are also implementing the same DST change; other countries may decide to make similar changes to DST rules.
Beginning in 2007, DST start and end dates will be: - Start date: Second Sunday of March (11 March 2007)
- End date: First Sunday of November (4 November 2007)
Systems or applications that process dates and times could be affected by this change. If not addressed, time and date calculations could be incorrect. |
| Important note: The following recommendations apply to users of IBM HTTP Server (based on Apache) on the following distributed operating systems: - AIX
- HP-UX
- Linux
- Solaris
- Windows
For users on z/OS: - IBM HTTP Server V6.1 for WebSphere Application Server: Only the following Run-time behavior section applies to the z/OS platform. Only applicable operating system changes are necessary.
- HTTP Server for z/OS V5R3 (not based on Apache): This information does not apply.
| IBM HTTP Server releases 1.3.26 and later use a Java-based installer. Java™ does not obtain information about time zones from the operating system, so the JRE must be updated to obtain the updated time zone rules. However, the only identified impact is to time stamps in install and uninstall log messages, so no action is recommended for this issue. |
The following Java applications are used for certificate and key management: - iKeyman
- gsk5cmd (older releases)
- gsk7cmd
The JRE or SDK used within these applications contains definitions of time zones which must be updated for daylight savings time changes.
The identified impacts are: - Application displays the expiration time incorrectly (off by an hour).
- Self-signed certificates could have a validity that is off by an hour in either direction. Note that the length of validity is normally a number of years.
Certificate creation is not impacted because the validity is determined by signer, not requester.
For IBM HTTP Server V6.1:
A JRE is installed with IBM HTTP Server in the install_root/java directory for use by iKeyman and gsk7cmd. This Java already includes fixes for the DST changes in the United States for 2007. However, fixes are not included for changes in other countries in 2007. IBM has provided a Java Time Zone Update Utility which can be used to update the time zone rules in these other areas.
For IBM HTTP Server V6.0:
A SDK is installed with IBM HTTP Server in the install_root/_jvm directory for use by iKeyman and gsk7cmd. IBM has provided a Java Time Zone Update Utility which can be used to update the time zone rules.
For IBM HTTP Server V1.3.26, 1.3.28, 2.0.42, and 2.0.47:
A SDK or JRE is not installed with IBM HTTP Server. It could have been installed with WebSphere Application Server, with the operating system, downloaded from IBM developerWorks, or obtained elsewhere. Required updates will depend on the supplier of the SDK or JRE. If IBM is the supplier of the SDK or JRE, the Java Time Zone Update Utility can be used to update the time zone rules. |
The Web server itself, and the security library used for SSL communication, obtain time zone information from the operating system and do not provide separate definitions of rules. Operating system updates, or manual configuration where advised by the operating system vendor, should be applied so that behaviors affected by time zone rules work properly.
Links to operating system maintenance are provided in the Daylight Savings Time flash for WebSphere Application Server.
The following are the identified impacts if no operating system changes are applied: - Time stamps in log and trace messages
- Output generated by the Web server for display in the browser
The HTTP protocol specifies that all date and time stamps are represented in GMT/UTC. Supported operating systems provide time stamps in GMT/UTC. Thus, time zone conversion is not performed for HTTP processing. |
For more information on the provision, see the Energy Policy Act of 2005.
| Date | Description | | 15 Feb 2007 | Added an important note to the DST fixes section. | | 7 Dec 2006 | Added links to the IBM Java Time Zone Update Utility. | | 9 Nov 2006 | Added link to the IBM DST alert site. | | 6 Nov 2006 | Original draft published. | | | | | | | | | Cross Reference information | | Segment | Product | Component | Platform | Version | Edition | | Application Servers | WebSphere Application Server | IBM HTTP Server | AIX, HP-UX, Linux, Solaris, Windows | 6.1, 6.0, 5.1, 5.0, 4.0, 3.5 | Advanced, Base, Express, Network Deployment, Single Server |
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| Product categories: |
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| | Software | |
| | Application Servers | |
| | Distributed Application & Web Servers | |
| | IBM HTTP Server | |
| | Runtime | |
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| Operating system(s): |
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AIX, HP-UX, Linux, Solaris, Windows
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| Software version: |
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1.3.28, 2.0.47, 6.0, 6.1
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| Reference #: |
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1248962
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| IBM Group: |
| | Software Group |
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| Modified date: |
| | 2007-02-15 |
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