In past years, daylight savings time began on the first Sunday in April and ended the last Sunday in October. This year, however, DST will begin on the second Sunday in March and end the first Sunday in November. This change, the first nationwide change in 20 years, adds a month to DST. Other jurisdictions to make adjustments this year include Canada, Bermuda, Brazil, and Western Australia.

The change is not without issue, however. Just as some computer systems had problems dealing with the switch to 2000, the new daylight savings time is requiring many users and administrators to prepare their systems for the new rules. According to Director of Communication & Middleware Technologies Gary Schwartz, many applications and operating systems will require patches to keep up. The situation is not nearly as hyped as it was for the “Y2K bug,” Schwartz said, but it will still cause issues to arise.

According to information on the Institute’s Help Desk website provided by Joseph Jackson of Carnegie Mellon University, some computer systems may experience problems with calendar programs, programs requiring synchronization, and time calculations failing to take the new rules into account.

“There is much less confusion, and the fix is much more straightforward,” Schwartz said. Most problems can be fixed by downloading a patch for the operating system, correcting the system time to take into account the new rules. Some applications, however, use their own method of calculating time and dates, and such programs may also require additional patches. For example, the Java runtime includes its own set of tables for calculating time zone information which is separate from the operating system, so it too requires an update.

This is not the first time that daylight savings time changes have occurred, as many changes to DST have taken place in Indiana, Australia, and Israel. However this year, as the entire population of the United States, Canada, and Bermuda make the switch to the extended DST, significantly more computer systems will be affected than have been in the past. “For many professionals, this is the first pervasive DST change they’ve been through with technology,” said Schwartz. In order to prepare the Institute’s systems for the change, education has been key, notifying administrators and users of the effects of the change and taking advantage of scheduled downtimes to apply the patches.

Changes in calculations and accounting for time and dates have had historical impacts as well. Back in 1752, the British Empire moved from the Julian calendar to the current Gregorian calendar. This change added 11 days to the calendar and moved President George Washington’s birthday from February 11, under the Julian calendar, to February 22, under the Gregorian calendar. In 1963, power in Los Angeles was switched from 50 hertz to 60 hertz. That change caused many clocks to run 20 percent faster.

Motives behind the concept of daylight savings time include energy conservation, more leisure time, and reduction in traffic accidents. According to one U.S. Department of Transportation study, DST was likely to reduce the country’s electricity usage by one percent. Also, with the work day starting earlier in the day, there would be more time left before the sun set during the summer. Finally, the same Department of Transportation study noted a 0.7 percent decrease in traffic fatalities and a reduction of between 10 and 13 percent in the commission of violent crimes.