In-Depth

A Guide to Daylight Saving Time Updates

The Daylight Saving Time changes may not have the impact of Y2K, but the ripples may give IT managers heartburn nonetheless

For the first time in 22 years, daylight saving time starts three weeks sooner and ends one week later than normal. Although the consequences from an earlier “spring forward” and later “fall back” doesn’t represent the level of threat imagined with Y2K, there are enough little snafus and “gotchas” to keep any IT manager busy for the next couple of weeks. IT must look well beyond the desktop; everything mainframes to phone systems to specialty equipment may give your system a problem.

The cause: the 2005 U.S. Congress passed an energy bill that shifted DST from the first Sunday in April and last Sunday in October to the second Sunday in March and first Sunday in November respectively. The changes, effective this year, move the start of DST from April 1 to March 11 and the end from October 28 to November 4. Also, Western Australia changed its DST times and Indiana moved from county-to-county to statewide observation of DST.

Dumb devices that have no clue about the day of week or smarter devices that don’t know the year need the usual manual adjustment. It’s the systems which automatically adjust to Daylight Saving Time that need further education.

It’s a matter of what time is right. Those who have scheduled appointments on a notebook or PDA for destinations in different time zones know the potential confusion.

The problem affects more than just calendaring, which by itself could have considerable productivity impact. Consider other time-oriented applications, including phone billing, time cards, automated payments, and freight or travel routing—anything where computerized time marks or schedules need to be real-world right can be affected.

Some systems-related items can be affected by the difference. Since both use the current time, logging into a Windows domain or getting a Kerberos ticket can be muddled by the difference. System logs and security information analyzers would have divergent time stamps. The hour-off stamp would not affect operations but will open the logs to suspicion in both legal proceedings and for auditors.

Unlike dumb devices, manually adjusting smart devices is twice the effort: one adjustment on the new DST shift day to compensate and another on the original DST shift day when the computer shifts itself.

These changes set IT organizations onto the patching quest for operating systems, middleware, and applications. Discovering the updates will require detective work. Many operating systems including Microsoft Windows, Unix/Linux, and Macintosh OS require updates. The problem is that most legacy desktop OSs are being left in the dust. Windows XP SP2 and Windows Server 2003 have updates available. If your company bought into extended support, patches are available for Windows 2000. Otherwise, you are on your own for registry patching or third-party patches for the remaining OSs.

For third-party solutions, Intelliadmin has YMMV freebie tools for Windows 9x and later, but it doesn’t handle non-English versions and omits some time-zone tables. A small company named Sharp Business Systems has a $500 enterprise license tool handles that NT 4 and later.

Mac’s OS versions 10.3 (Panther) and 10.4 (Tiger) have updates. OS 8 and 9 were manual corrections anyway. OS 10.0 through 10.2 are on their own or third-party solutions.

Most handheld devices, including Palms, Pocket PCs, and smartphones of any OS need an update. The wide variety of PDAs without updates will need manual intervention and calendar vigilance.

Many pieces of middleware, Webware, database, and server applications require updates. The list includes Apple’s WebObjects, Oracle databases, and Microsoft Exchange. Additionally client-side only applications, such as IBM Notes and Microsoft Outlook, need refreshing.

The most problematic may be Sun’s Java and Java runtime environment (RTE), whose many versions accompany many applications. Since the RTE installer doesn’t remove the five or more older version when installing the new, many systems may have over a dozen older versions still sitting on their hard disks.

All Linux distributions require updates. Most distributions in the last couple of months have the correct settings for 2007, and more Linux DST updates concern Java than other internals.

Confused? Join the club. A quick call to IBM’s press relations asking if Linux or the mainframes were affected by the new DST got a response of “no.” A trip to the IBM Web site says “yes” for the zSeries and everything from servers to routers to printers. HP is as inclusive in its DST 2007 at its site.

Just as you’ve heard on late-night infomercials, “Wait! There’s more!” Many pieces of your network fabric including managed routers and switches, firewalls, UTMs, and other related appliances will require updates, which translates to updates from vendors such as Checkpoint, Cisco, and Juniper Networks.

In many cases, patches for the DST changes are rolled up into larger updates that cover other issues. In many cases, the DST changes have been available for several months, so your IT teams will probably have tested and pushed patches to endpoints, heavy iron, and everything in between with change logs everywhere. For everything else, it’s feet on the ground and e-mails to everyone to stay calendar-aware for the next couple of weeks (and again at the end of October).

The real heartburn is a codicil within the Energy Act of 2005 which charges the Department of Energy to access and report to Congress the impact of the change—which potentially means we could repeat this exercise again in another year or so.

DST Support by Company

About the Author

Chris DeVoney is a Seattle-based 30-year veteran of computing who has written numerous technology books and articles. He is currently an IT specialist within the University of Washington.

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