Daylight Saving Time: Spring Ahead with Caution – and Double Check Your Appointments
This coming Sunday morning, while most people are asleep, the United States and parts of Canada will switch to Daylight Saving Time at 2 a.m. local time. This is in accordance with the Energy Policy Act of 2005 and once again is three weeks earlier than in previous years. If you don’t think that these changes are a big deal, change the time on your laptop by an hour and see what happens. The impact of this seemingly minor change extends well beyond computers, to legions of business travelers and mobile knowledge workers, among others.
Once again, the United States will be out of sync with the rest of the world for longer than usual. Europe used to change its clocks to “Summer Time” (in the U.K., it’s BST or British Summer Time; in Germany and Austria, it’s “Sommerzeit”) one week before the U.S. Now most of Europe will switch to Summer Time on March 29, three weeks later. [Most of Asia, Africa, and South America do not observe Daylight Saving Time at all.]
As if to illustrate this specific point, I just discovered that a recurring bi-weekly meeting that was scheduled by a client based in Israel using Microsoft Outlook mysteriously moved to noon EDT on my calendar for its two occurrences in March. For meetings in April, it remained at the original time, 11 a.m. EDT.
Daylight Saving Time ends on November 1 in North America; in the European Union, Summer Time ends on October 25.
Daylight Saving Time is a system of managing the changing amounts of daylight that occur during the year, with a goal of maximizing daylight hours during typical waking hours. It was first proposed by Benjamin Franklin in 1784, who believed it would save an “immense sum.” It was not broadly adopted until the early twentieth century when the U.S. temporarily enacted Daylight Saving Time as an energy-saving measure.
By adjusting clocks ahead by an hour, people can have more daylight available during the workday. For example, in the case of someone who typically awakens at 7 a.m., since in the spring the sun rises earlier each day, an individual would have to wake up at 6 a.m. to take advantage of the additional daylight. Instead, by moving the clock ahead by one hour, that person can continue to wake up at 7 a.m. and enjoy more daylight in the evening hours.
The last change to the Daylight Saving Time schedule was in 1986, when legislation changing Daylight Saving Time from the last Sunday in April to the first Sunday in April was enacted.
But recent studies indicate that the savings may be illusory. One study demonstrated how a switch to Daylight Saving Time across the entire state in April 2006 cost Indiana households an additional $8.6 million in electricity. Another study suggested that the temporary extension of daylight-saving in two Australian territories for the 2000 Summer Olympics increased energy usage.
On the other hand, the American Council for an Energy-Efficient Economy, a nonprofit group, estimated that the cumulative benefit of the change through the year 2020 will be a savings of ca. $4.4 billion and 10.8 million metric tons less carbon sent into the environment. According to the U.S. Department of Transportation, for every day we are on Daylight Saving Time, we trim one percent of the country’s electrical consumption.
Last year, companies sent out all-hands memos to employees asking them to help identify systems that might be impacted by the time change. These systems ranged from automated wake-up systems in hotels to systems that schedule airline crew members and slot aircraft for gates. In addition, many computer-to-computer systems might have also been impacted.
Most knowledge workers should be covered by now, at least insofar as their desktop or laptop computers are concerned. Microsoft released a single global time zone update for Windows XP Service Pack 2 and Windows Server 2003 (and for Windows Server 2003 Service Pack 1) that automatically installed. This update included updates for all DST-related changes from 2007 or that have taken place since the operating system’s original release. The updated time zone definitions ship with Windows Vista. Windows XP SP1 and older operating systems have passed their end of support dates and did not receive the update although they can be manually updated in some cases.
That covers operating systems but doesn’t mean that we are out of the woods yet. Most current programs with calendar support should have been updated by now but if yours has not, any meetings that fall within the extended Daylight Saving Time period before the application of extended DST rules will appear incorrectly after the extended DST rules have been applied, namely they will appear an hour later than originally scheduled.
What you can do to avoid problems:
First, double check any calendar entries or plans for the period March 9 – March 30, 2009.
Second, make certain to adjust or update your operating system to apply the changed Daylight Saving Times rules if this hasn’t already taken place. PDAs such as Palm Treos or BlackBerry devices should also be updated.
Third, remember that Daylight Saving Time is not observed in Hawaii, American Samoa, Guam, Puerto Rico, the Virgin Islands, and Arizona (with the exception of the Navajo Nation). Until 2006, the counties in the Eastern Time Zone of Indiana did not observe Daylight Saving Time and remained on standard time year round. As of April 2006, all of Indiana observes Daylight Saving Time.
Finally, get a good night’s sleep.