Daylight Savings: Y2K All Over Again?

It seemed like a good idea at the time.

In 2005, as the price of gasoline spiked, Congress quietly passed a measure to begin daylight-saving time three weeks early this year. If the sun stays up later, went the logic, U.S. energy consumption would go down.

The problem is that while they told us all of the switch, they didn't tell our computers or our cell phones -- or any of the zillion other digital clock-driven devices that have come into our lives since Congress last messed with the calendar in 1986.

"Even little stones that are thrown in a pond have a lot of unintended ripples, and this is certainly one of them," said Jeffrey Hammond, an analyst at Forrester Research in Cambridge, Mass., who has kept tabs on all the updates and software patches that companies are now making.

"Planes won't fall from the sky," he said, "but there are going to be a lot of little, minor annoyances that make people's days a little more hectic, a little more painful."

What Will Be Affected

Daylight-saving time would ordinarily have begun on the first Sunday in April. Instead, it'll begin this weekend.

If you're like most of us, you'll get up Sunday morning and reset the clock in the kitchen, and the one on the microwave, and the old clock in the living room, and so on and so forth.

But what about your computer? Or the clock in your cell phone? Or let's say there's a stock you're hoping to buy online just before the market closes Monday.

Here are some things of which computer specialists say you ought to be mindful:

Computers: If you have a new one, running, say, Windows Vista, Windows XP Service Pack 2, or Apple's OS X, you'll likely be fine. Newer machines either know that daylight-saving time has moved up, or software patches were sent out online.

If you have an older operating system, though, you'll have to change the computer's clock on your own, and you may have to un-change it when it thinks the clock is supposed to spring forward on April 1. No big deal, but there are tens of millions of older machines out there.

Electronic Calendars: Microsoft Outlook is just one of many programs people use to keep themselves on schedule. Stand forewarned: Even Microsoft says to get on the phone and check your appointments during the three weeks in March when we were supposed to be on standard time.

Cell Phones: You should be OK, but you should also pay attention, say tech consultants. Your cell phone typically receives time signals from your service provider, and the major ones have been updating their systems to avoid trouble.

But some consultants say you ought to check your bill when it comes at the end of the month. That long call you thought was finished before off-peak hours ended? It may not have been.

Handhelds: If you have a BlackBerry, a Palm or the like, many models will need an update. If you have one through your employer, they may well be taking care of it for you. If not, or if nobody's gotten in touch with you, go to the company Web site for instructions.

Online Trading and Banking: This is an area where everything could be fine, or things could get tricky. If you're making any time-sensitive transactions, double-check. Some systems could be an hour off.

International Calls and Meetings: Keep in mind that the United States and Canada are switching their clocks, but 180-odd other countries are sticking to their guns. If you planned an overseas call for a specific time, you may be surprised. Great Britain, for instance, does not start "summer time" until March 25. London is usually five hours ahead of the U.S. Eastern time zone; for two weeks, it will be only four hours ahead.

Video Recorders: Do you have a TiVo? Or, for that matter, an old but reliable VHS recorder? This is another case in which to be wary. Newer models may have been sent software updates online, but older ones may hiccup.

"The more connected people are, the more likely they are to see the problem," said Forrester's Hammond. "If you've TiVo'd in 'Ugly Betty' Monday night on ABC and you've got an older TV, you might end up with 'Men in Trees' instead."

Déjà vu All Over Again

IT specialists at major companies have been working long hours, updating computer networks and transmitting commands to remote computers. But the Geek Squad, an operation that fixes computers for consumers and small businesses, says it has not been getting a lot of calls.

Why not? Perhaps, they told us, not a lot of people are focusing on the issue. Or maybe, said one consultant, we're seeing a case of "Y2K backlash."

Remember back in the late 1990s as the world fretted about computers that were going to melt on the stroke of midnight Jan. 1, 2000? Billions of dollars were spent on new equipment, new software, even emergency supplies bought by people worried that modern civilization would come to a halt. NASA even had a space shuttle in orbit over Christmas, and shortened the mission just to be safe.

In the end, the clocks struck midnight, people partied, the new millennium came, and virtually nothing went wrong.