October 24, 2006 > It's about time
It's about time
by Todd Griffin
Spring forward, fall back: it's that time again. This Sunday, October 29, at 2:00 a.m., it magically becomes 1:00 a.m. "Falling back" gives us an extra hour of sleep, though we may find much of that hour consumed with locating all our clocks and getting them set properly. How did Daylight Savings Time (DST) come about, and is it really worthwhile?
Time zones were first used by the railroads in the U.S. starting in 1883. Prior to such rapid transit, there was no need to coordinate timekeeping across the country. In 1918, federal law codified these "rail zones" into the time zones we have today.
The idea of adjusting clocks forward during summer months to reduce the cost of lighting was put forward by Benjamin Franklin in 1784, though few took his proposal seriously. Keep in mind oil lamps and candles were the primary forms of lighting at the time. More than 100 years later, Britain, Germany, and the U.S. implemented DST briefly during World War I.
In the U.S., the law governing DST is the Uniform Time Act of 1966. It does not require states to participate in DST, but defines how it must be implemented for those that choose to do so. Today, 40 years later, the entire U.S. has chosen to participate, with the exception of Arizona, Hawaii, Puerto Rico, Guam, the Virgin Islands, and American Samoa. Because of the relative proximity to the equator of these areas, daylight periods are more uniform year-round, the climates are warm, and the benefits of DST are limited.
Similarly, most major industrialized nations, except Japan and those in equatorial regions, have implemented some form of DST. In the southern hemisphere, DST is observed from October to March. The entirety of China has a single time zone, and it does not observe DST. It will be interesting to see if increasing industrialization there changes that policy.
Here in the U.S., new legislation (the Energy Policy Act of 2005) has mandated an increase in the period of DST each year. Up until now, we have turned the clocks forward the first Sunday in April and back the last Sunday in October. Starting in 2007, DST will begin the second Sunday in March and end the first Sunday in November.
The primary rationale for DST is energy conservation. The increased daylight during the evening hours reduces the need for lighting. Of course more lighting is used in the morning, but based on the sleep schedules of most people, this is more than offset by evening savings. The overall summer energy savings from DST is thought to be about one percent. This is why DST is observed only in the summer; the increased need for lighting in the dark winter mornings would negate the evening savings.
Proponents of DST posit further benefits. With the additional evening daylight, people are more likely to engage in outdoor activities, which reduces energy used by appliances in the home. In addition, a reduction in traffic accidents has been found in some studies, presumably attributable to fewer people commuting and traveling in darkness. Finally, there is a qualitative benefit: many people prefer the extra daylight late in the day, which provides opportunities to enjoy the warm summer evenings.
On the other hand, there are those who are opposed to DST for a variety of reasons. They counter the accident statistics by pointing to a sharp increase in accidents immediately after the spring and fall time changes, due to the disruption of sleep patterns. While most people require a few days to adapt to a one hour shift in schedule, those with sleep disorders and related ailments may find it more difficult.
Farmers often criticize DST, since they tend to rise early, and often must tend to chores based on the sun, not the clock. This can place them "out of synch" with the rest of the community. They also complain that livestock, particularly poultry, have difficulty adjusting to a change in schedule.
Some people question the fundamental justification for DST, energy conservation. Many studies confirming the savings associated with DST were conducted several decades ago, when air conditioning was not as widespread. Critics claim DST results in increased use of energy-gobbling air conditioners in the evening hours, since the heat of the day has been shifted one hour later. This is the principal reason Arizona has chosen not to participate.
But for many of us the most significant objection to DST is simply having to adjust the clocks twice a year. Fortunately, the increasingly popular "atomic clocks" and most personal computers do this automatically, but most of us still have a lot of clocks to reset, in addition to our biological clocks.
Some have proposed the radical approach of adopting a Universal Time (UT), in which the entire earth is on the same time, eliminating time zones and DST. Factories, offices, stores, and schools would develop schedules based on local daylight hours, and could change them seasonally if they saw a benefit. While we might have to adjust our alarm clocks once in a while, the time would never change.
It would take some getting used to working, say, 2:00 p.m. to 11:00 p.m., but those would be the same daylight hours we work now. Scientists and the military have used forms of UT (Greenwich Mean Time or GMT for civilians or Zulu time used by the military) for decades. When planning an invasion or a rendezvous with an orbiting satellite, confusion about time can be disastrous.
This idea also has benefits to the global business climate in which we work. A meeting may take place at different times and even different days for the various participants. With UT there would never be confusion about when a meeting starts, how many hours a flight lasts, or how to date a contract. When it's 8:00 a.m. Monday in San Francisco, it would be 8:00 a.m. Monday in Tokyo, Kabul, and London too.
While implementing UT is an interesting concept, it would require the cooperation of countries around the world, and is not going to happen anytime soon. In the meantime, let's turn those clocks back and enjoy the extra hour of sleep. We don't have to pay it back until next spring.