The US is adopting a new Daylight Saving Time (DST) schedule from 11 March, giving the country an extra four weeks with the clocks forward an hour for energy-saving reasons.

While it's primarily a US problem, it will have an effect elsewhere, as it now means that, according to Gartner, between 11 March and 25 March this year there will be a six hour time difference between London and New York, instead of the normal five hour difference.

So IT vendors have been scrambling to prepare patches, work-arounds and other fixes for their products to help their customers prepare for the changes.

Here is a sampling of some of the major IT vendors and the status of their patch availability:

  • Microsoft -- The new Windows Vista operating system already includes the updated DST rules, but earlier versions of Windows will need to be changed. For Windows XP Service Pack 2, Windows Server 2003 and Windows Server 2003 Service Pack 1, Microsoft will release a single global time-zone update, which will include updates for the US time change.

    Earlier versions of Windows, including XP SP1 and NT 4.0, are no longer supported but can be patched manually using Microsoft's tzedit.exe utility. That allows administrators to create and edit time-zone entries for the Date/Time settings in the Control Panel. Other affected applications include Windows Server, Windows Mobile, Windows SharePoint Services, Exchange Server, Office Outlook, Dynamics CRM, Biztalk Server and Entourage, according to the company. Corrective updates will be released through Microsoft Customer Support Services, hot fixes incorporated in Knowledge Base articles, Windows Update, Microsoft Update, Windows Server Update Services and the Microsoft Download Center. Some of the tools and patches are available now, with the remainder scheduled to be released through early March.

    A detailed summary of the effects of the DST changes on Microsoft products is available at the company's Web site. A Microsoft spokesman could not be reached for comment about the matter.

  • Sun Microsystems -- Sun is offering free patches for its Solaris Unix operating systems, Versions 8, 9 and 10, while patches for earlier Versions 5, 6 and 7 will only be provided for a fee, according to the company. Patches for Java applications, including the Java Runtime Environment (JRE), will also have to be applied, according to the vendor.

    More recent JRE versions -- including Java SE 6 or later, J2SE 5.0 Update 6 or later, J2SE 1.4.2_11 or later, and J2SE 1.3.1_18 or later -- already include new time rules to handle the DST changes, according to Sun. Older versions can be replaced with the newer, corrected versions, or administrators can use Sun's tzupdater tool from the Java SE download page to update Versions 1.4 or later.

    Users of older Solaris operating systems do have another alternative to updating the systems with newer releases, however. At least one third-party vendor, services and support provider Terix Computer Service, has announced free software to update the DST issues in Sun Solaris 5, 6 and 7. Larry Quinn, director of sales at the Sunnyvale, Calif.-based company, said Terix originally created the patches for its own customers, then later decided to offer them for free to all users of older Solaris systems.

  • IBM -- Details about the DST changes for a wide range of IBM products can be found at the vendor's special DST Web site, along with more detailed information about related problems with Sun Java. IBM also includes specific information about running its products along with Microsoft Windows, as well as a detailed FAQ (download PDF) about the DST change.

    Some IBM products can be updated now, while other applications will include DST updates in the next regularly scheduled maintenance releases, according to the company.

  • Cisco Systems -- Information on DST issues and Cisco products can be found at the vendor's Web site.

  • BEA Systems -- BEA WebLogic users can get information on how to deal with the DST changes at the company's Web site.