Spring Ahead with Caution
This coming Sunday morning, while most people are asleep, the United States and parts of Canada will switch to Daylight Saving Time at 2 h local time. This is in accordance with the Energy Policy Act of 2005 and is three weeks earlier than in previous years (it ends one week later than usual, on the first Sunday in November). If you don’t think that these changes are a big deal, change the time on your servers by an hour and see what happens. Its impact will extend well beyond computers, to legions of business travelers and mobile knowledge workers, among others.
The change means the United States will be out of sync with the rest of the world for longer than usual. Europe used to change its clocks one week before the U.S. Now most of Europe will switch to daylight saving time on March 25, two weeks later. [Most of Asia, Africa, and South America do not observe daylight saving time at all.]
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 but was not broadly adopted until the early twentieth century. 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 h, since in the spring the sun rises earlier each day, an individual would have to wake up at 6 h 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 h 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.
In case you are wondering why we are doing this now, it’s not just to enjoy a little bit more sunlight. Although the savings are almost minuscule on an individual basis, the American Council for an Energy-Efficient Economy, a non-profit 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.
Since late last year, companies have sent out all-hands memos to employees asking them to help identify systems that might be impacted by the time change. These systems range 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 may also be 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 will also 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. Software that supports calendar entries, such as Lotus Notes and Domino and Microsoft Outlook and Exchange, and other time-zone-aware calendar systems, are also impacted. If you created an entry that falls within the extended Daylight Saving Time period before the application of extended DST rules, it will appear incorrectly after the extended DST rules have been applied. Entries that fall between March 11, 2007 and March 31, 2007 will appear an hour later than originally scheduled. Entries that fall between October 28, 2007 and November 4, 2007 will appear an hour earlier than scheduled. For example, if you create an entry today for 10 h on Monday, March 12, 2007, the entry will display at 11 h after the rules are applied.
What you can do to avoid problems:
First, double check any calendar entries or plans for the period March 11 - March 31, 2007 and October 28 – November 4, 2007.
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.
Jonathan B. Spira is CEO and Chief Analyst at Basex.