April 19, 2004


Switch to daylight-saving said to reduce accidents, crime (Japan Times, 4/20/04)

Annual traffic accidents can be reduced by about 1.1 percent if Japan adopts daylight-saving time, according to projections released Monday by the Japan Productivity Center for Socioeconomic Development.

The center said the economic effect of turning the hands of the clock ahead an hour between April and October would be worth some 46 billion yen a year.

In recent years, the annual number of traffic accidents has hovered around 940,000, and police say statistics show they usually occur around dusk.

Center officials said calculations based on the percentage of accidents vis-a-vis traffic volume by time and season of occurrence show that about 10,000 accidents can be avoided by shifting to daylight-saving time.

It also said that under a daylight-saving regime, 10 percent fewer women would have their purses snatched on their way home from work and 4 percent fewer would be similarly victimized while shopping in the early evening.

We've too many chevaux de bataille of our own to ever indict others for theirs, but the psychotic hatred of libertarians for Daylight Savings Time is at least amusing.

Posted by Orrin Judd at April 19, 2004 8:43 PM

After resetting the 20+ digital clocks in my house twice a year, I think that DST "hatred" is perhaps quite reasonable.

Every electronic device now has a handy-dandy built-in digital clock--stove, microwave, heck even (high-end) refrigerators.

Posted by: ray at April 19, 2004 10:09 PM

Most of my devices reset themselves automatically, and this seems to be the trend, too. (Then again, my digital watch doesn't handle intercalation, which I didn't notice for several days this year.) What this mean is that thanks to modern electronics, the dates of the change are immune to congressional meddling for decades to come.

The real solution is to exploit that automatic setting ability and arbitrarily set sunrise at 06:00 (or sunset at 19:00), and change the time every day to reflect that. Add in the ability to know exactly where one is via GPS and in the future the centuries where "railroad time" replaced a local, sun-based time will be considered an aberation.

Posted by: Raoul Ortega at April 19, 2004 10:31 PM


Setting sunrise or sunset to a fixed value makes time nonlinear or discontinuous due to cyclic variations, called the equation of time, caused by the earth's orbit. Using local time everywhere returns to the chaos before the time zones, requiring continual conversions of schedules and elapsed times between different points.

A more rational approach would simply be universal time everywhere, adjusting activity schedules to different time ranges at different localities. Schedules are automatically synchronized, and elapsed times easy to calculate.

Posted by: jd watson at April 19, 2004 11:04 PM

Bless you, OJ!

You're right, too - it's a little harder to find good WOTD fodder than I might have thought.

Posted by: Bruce Cleaver at April 20, 2004 6:45 AM

I thought French had been barred from the blog, even ironic, po-mo French.

Posted by: David Cohen at April 20, 2004 10:22 AM

I think we should establish DST as Standard time.

Posted by: genecis at April 20, 2004 12:04 PM

>Every electronic device now has a handy-dandy
>built-in digital clock--stove, microwave, heck
>even (high-end) refrigerators.

(And don't forget the clock-radios in the bedrooms or the actual clock in your car.)

And no two have the same method of resetting. Each and every one resets completely different.

Posted by: Ken at April 20, 2004 12:48 PM

I don't have a problem with DST. Or with standard time. Just pick one. Or split the difference. I don't care as long as I'm not inconvenieced twice a year by Congress trying to please hick farmers.

Posted by: Mike at April 20, 2004 3:33 PM

Can anyone assist a technologically-challenged guy to solve a mystery. On a trip to the Gulf last month, we noticed my wife's cell-phone clock changed the time automatically after we crossed into Alabama and Central Time. She had made a call before we noticed, so on the way back we watched more carefully. Did the same thing automatically two minutes after we crossed into Georgia. How did it know where we were?

Of course I have a religious explanation, but maybe somebody here can give a materialist one. Either way, I didn't like it one bit.

Posted by: Peter B at April 20, 2004 5:29 PM


The cell phone system is based on very acurate time synchronization. Whenever you enter a new area your phone resynchs with the system.


I have thought about this a long time, as it were. it is a good idea, but it has a problem. It is very inconvienent to have the date change during business hours. An alternative that could work would be expanded time zones. e.g. All of North America on on Z+6 (CST) would work fairly well except Alaska and Hawaii would probaly be on a pacific time Z+11 South America might unify on Z+3 and Europe and Africa on Z-1

Posted by: Robert Schwartz at April 20, 2004 11:22 PM


Interesting suggestion -- I had not thought of the business implications. My only point was that time is an arbitrary construct. We could use the ancient definitions which fixed sunrise and sunset, resulting in nonlinear time, since the length of the day varies throughout the year (this makes physics, whose laws are based on uniform time, extremely difficult). We could use uniform local time, which makes schedules between different localities difficult (the railroad problem). The military uses "Zulu" time (Coordinated Universal 'Greenwich' Time) to coordinate their activity, which seems to work well.

Why does the date even have to be a factor? Why not use elapsed time since the beginning of the year (i.e., stardate XXXXXhours, XXmin, XXsecs, Year XXXX?). Or the astronomical system, i.e julian day and time?

Posted by: jd watson at April 21, 2004 5:30 AM

And BTW Orrin, not all libertarians have some "psychotic hatred" of daylight savings time. Some of us understand that time is an arbitrary construct of the human mind!

Posted by: jd watson at April 21, 2004 5:40 AM

If it's an "arbitrary construct of the human mind", how come I'm getting steadily older?

Posted by: Ken at April 21, 2004 1:23 PM


I think the maxim is diffrent strokes for diffrent folks. Most of us, do not conduct scientific experiments or military operations. We live at the pace of hours, days and months. Dates are important. Yesterday was my 24th anniversary -- and no I did not forget -- two dozen roses.

Banks and other markets need to close their books at the end of their days to record their business. And humans schedule events including anniversaries, doctors appointments (I must take my mother to hers Friday at 2) and school tests (Lila had an algebra mid term yesterday morning) on that scale.

2.345684 X 10^15 sec from -4739 BCE. is not going to do it for most of us. Computers don't mind a little extra computation. In Unix and C, the date is determined by keeping the total number of seconds from some arbitrary base (1972-01-01 IIRC) and calculating the date and time on the fly from that number. It turns out that the problem is not nearly as simple as it might seem because of things like leap seconds. See:


My bottom line is that the simplest thing that could be done is my proposal for big time zones.
One year when when the eastern US is on EDT (Z+6) it just stays there when CDT (Z+7) switches to CST (Z+6) a small number of such steps would put all of north america on the same time. There after adjustments would be in the opening and closing of local institutions. to match the rising of the sun.

p.s. julian dates do not work because they turn over at noon and do not have years.

Posted by: Robert Schwartz at April 21, 2004 2:01 PM