A federal law adopted during World War I to save energy for war production forces you to change your clocks either forward or backward each spring and fall, potentially wreaking havoc on your plans. But while gadgets without a network connection have to be updated manually in response to Daylight Saving Time, wired gadgets can change the time themselves by communicating with a home base or checking against an internal calendar.
Cell phones, on the other hand, are perhaps most advanced because they read the correct time based on signals from local cell towers; this is the same technology that allows cell phones to update their clocks when you travel across time zones. Even atomic watches, such as Timex and Casio, and some TVs and VCRs can adjust times based on radio signals.
Meanwhile, TiVo and other digital video recorders (DVRs) provide a Daylight Saving service.
“Our TiVo boxes get the new daylight savings time when they call into our service, which is done daily,” said Krista Wierzbicki, the public relations director at TiVo. “The TiVo service knows the zip code associated with each of our boxes as well. That said, when the TiVo box calls in on daylight savings it pings the service and then the box is updated.”
Luckily, other gadgets have internal calendars that have been set to adjust to the biannual time change. This is true for computers, iPods and smartphones, such as iPhones and BlackBerry devices.
In 2007, when the Daylight Saving Time start and end dates in the U.S. changed, many people had to download a patch to update the software in various devices, such as PCs and BlackBerrys, while iPods and other MP3 players had to sync the time by plugging into the computer.
But given a glitch in the iPhone alarm clock that caused many Europeans and Australians to sleep in last November, you should probably have a back-up alarm clock and reset the alarms in your devices after the time change.
Remember to "spring forward" when Daylight Saving Time happens on March 13, 2011.