Sunday, March 9, 2008

Daylight Savings Time

Ah, Daylight Savings Time starts today. Time to wander around and hope I find all the clocks that need to be reset, then try to remember how to reset the clocks in the cars. Forget about resetting the clocks on the VRC player - I don't even try. And all so that we can have the sun set at 10 pm in June and July, which makes it impossible to get kids to bed at any reasonable hour and delays Fourth of July fireworks until 10:30 pm. Maybe DST makes sense further south, where the summer day is shorter, but this far north, our days are already long enough to accomodate any reasonable evening activities. It is just a twice-yearly headache that further disconnects us from the natural world.

But then, standard time in general is an artifact of the industrial world anyway, not the natural world. It used to be that different towns had different times, all based on setting noon when the sun was highest in the sky. But once the railroads became big enough to cross long distances, it became a nightmare to set and publish timetables that took into account all the different "zones", especially since each railroad used its own time. In response to the chaos, the railroads created a series of standard time zones on November 18, 1883, to be used as "railroad time"; most cities adjusted their local time to match the railroads and so, without any government intervention, US time was standardized. Like all averages, standard time zones work best for the middle; in this case the middle of each zone has noon approximately when the sun is highest, but the further east or west you go, the more disconnect there is. People in the east edges of the zones tend to be the most discontented and often petition to be added to the zone to the east so that they can gain one extra hour before sunset.

That extra evening hour is pretty compelling to a lot of people and it is the most common argument given for Daylight Savings Time (DST). Back when lighting was the biggest user of electricity, adding an hour of daylight at the end of the day, when people tend to be active (at least in urban areas), saved an hour of lighting and therefore saved energy. This is why DST was adopted during WWI, but it was so unpopular among a population that tended to go to bed and get up early that it was repealed as soon as the war was over. In WWII, War Time, year-round daylight savings time, was adopted from February 9, 1942, to September 30, 1945, to save energy. After WWII, DST was optional for states and cities, resulting in exactly the chaos that the railroads were hoping to eliminate in 1883, but this time more industries were affected. Finally, in 1966, uniform clock times and DST were instituted, setting up our current clock systems.

The only problem with the theory that an extra hour of evening daylight saves energy is that all the original studies were done before air conditioning became common. With air conditioning, that extra hour of daylight in the day means an extra hour of air conditioning - more than negating the energy savings in an hour less of lighting. One recent study shows that in Indiana, switching to DST costs families an extra $8.6 million in energy costs annually. While it is hard to quantify benefits to DST, people have had fun quantifying the costs. For instance, IT expenses have been calculated to be at least $300 million each time the clocks shift. Farmers still hate the switches, since the animals don't have clocks to be reset so easily; dairy cattle in particular don't like to change their schedules. All so that people in the south can have an extra hour of sunlight for their barbecues and politicians can look like they are accomplishing something.

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