Fall Back: Europe Moves to Winter Time, U.S. Changes Clocks Next Weekend
Europe and the U.S. fall back - at different times
Europe set its clocks back one hour to “winter time” at 1 a.m. GMT Sunday. Next Sunday morning, while most people are still asleep, the United States and parts of Canada will switch back to Standard Time at 2 a.m. local time.
The November change is in accordance with the Energy Policy Act of 2005 and once again is one week later than in years before the 2005 Act. 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.
For the coming week, the United States will be out of sync with a good part of the rest of the world (most of Asia, Africa, and South America do not observe Daylight Saving Time at all).
Last March, as if to illustrate this specific point, I discovered that a recurring bi-weekly meeting that was scheduled by a colleague based in Israel 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 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 in the spring, 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.
Prior to 2005, the last change to the Daylight Saving Time schedule was in 1986, when legislation changing the onset of Daylight Saving Time from the last Sunday in April to the first Sunday in April was enacted.
But recent studies indicate that the energy 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.
Most devices including laptops and desktop computers (not to mention servers), should have been updated by now but it still pays to double check. 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.
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.
Oh, and get a good night’s sleep.
Jonathan B. Spira is the Chief Analyst at Basex.
October 25th, 2009 11:50
Turkey did the switch at 4AM this morning (Sunday Oct 25th). This had an interesting side-effect as I was flying from Shanghai to Istanbul during the transition. I wondered why the plane was reporting time an hour later than I had set my watch to but it also showed us landing an hour late. Turns out, of course, that the plane was correct about the takeoff time but wrong about the landing time.
I can understand getting this wrong – it’s the kind of thing the program (or programmer) just doesn’t deal with (same as a good UI on the per-seat user interface for the screen). Another related problem with calendar events is that the syntax doesn’t have good ways to deal with rich time representation. How can I say the meeting is 2PM in Istanbul and doesn’t change when the daylight changes? And is an all day meeting really all day or should the end points change?
More fun is when you have multiple operating systems and reboot and each tries to correct for DST. I pushed for putting the time zone in the nonvolatile RAM rather than in the OS but I didn’t convince people.
It’s a reminder of why Y2K wasn’t a big deal as these kind of issues are endemic but not a big deal because we take them in stride and don’t pile them on top of each other.
It’s also a reminder why the leap second is so incredibly stupid – time is approximate to the nearest hour and we care about nanosecond precision? And China has just one time zone – I’d like to understand more about how that works in practice.
Well enough for now – my body is zoning out …
October 25th, 2009 19:11
A follow-up note – my wonderful Panasonic DMC-TS1 is able to keep local time as a delta off the base time but, alas, it doesn’t know about these changes. How do devices deal with these issues as they get smarter but not wiser?
October 26th, 2009 08:23
There is only one “time zone” which is correct all the time and that’s UTC.
My day job is in a company with offices on both coasts of the US, two sites in China and two in India. Organizing a meeting is agonizing because everyone uses local time and it’s a continuing battle to get anything right. I have tried many times to convince people that meeting planning should be done in UTC
so at least that source of confusion is eliminated. But no. Everyone tries to
explain how that would be complicated. Somehow knowing just their
own UTC offset is seen as more complex than knowing the full cross-product of
relative offsets. On their own heads be it.
October 26th, 2009 12:01
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