PCs May Not Be On Time For Daylight-Saving Time
February 14, 2007
By BRIAN BERGSTEIN, Associated Press
For three weeks this March and April, Microsoft Corp. warns that users of its calendar programs “should view any appointments … as suspect until they communicate with all meeting invitees.”
Wow, that’s sort of jarring. Is something treacherous afoot?
Actually, it’s a potential problem in any software that was programmed before a 2005 law decreed that daylight-saving time would start three weeks earlier and end one week later, beginning this year.
Congress decided that more early evening daylight would translate to energy savings.
Software created earlier is set to automatically advance its timekeeping by one hour on the first Sunday in April, not the second Sunday in March (that’s March 11 this year).
The result is a glitch reminiscent of the Y2K bug, when cataclysmic crashes were feared if computers interpreted the year 2000 as 1900 and couldn’t reconcile time appearing to move backward.
This bug is much less threatening, but it could cause head-scratching episodes when some computers are an hour off.
The problem won’t show up only in computers, of course. It also will affect plenty of non-networked devices that store the time and automatically adjust for daylight saving, such as some digital watches and clocks.
But in those instances the result will be a nuisance (adjust the time manually or wait three weeks) rather than something that might throw a wrench into the works.
Cameron Haight, a Gartner Inc. analyst who has studied the potential effects of the daylight-saving bug, said it might force transactions occurring within one hour of midnight to be recorded on the wrong day. Computers might serve up erroneous information about multinational teleconference times and physical-world appointments.
“Organizations could face significant losses if they are not prepared,” the Information Technology Association of America cautioned this week.
A common fix is a “patch” that reprograms systems with the updated start and end dates for daylight-saving time.
Some of these updates are targeted at specific systems, and others have wider implications - such as one from Sun Microsystems Inc. for older versions of the Java Runtime Environment, which often fuels applications on computers and Web pages.
Microsoft planned to send its daylight-saving patch to Windows PCs with the “automatic update” feature on Tuesday. Users with automatic updates turned off should download the patch from Microsoft. (New machines running Windows Vista are immune because Vista was finalized after the 2005 law passed.)
However, computers running anything older than the most recent version of Windows XP, known as Service Pack 2, no longer get this level of tech support.
Owners of those PCs should go into the control panel and unclick the setting that tells the machine to automatically change the clock for daylight-saving time. They have to make the change themselves when the moment arrives.
Roy Cooke A happy NACHI member