Rationale & original idea 
The main purpose of Daylight Saving Time (called "Summer Time" many places
in the world) is to make better use of daylight. A poll done by the
U.S. Department of Transportation indicated that Americans liked Daylight
Saving Time because "there is more light in the evenings / can do more in
the evenings."

Daylight Saving Time also saves energy. Studies done by the
U.S. Department of Transportation show that Daylight Saving Time trims the
entire country's electricity usage by a significant, but small amount, of
less than one percent each day with Daylight Saving Time. We save energy
in both the evening and the morning because we use less electricity for
lighting and appliances.

Energy use and the demand for electricity for lighting our homes is
directly connected to when we go to bed and when we get up. Bedtime for
most of us is late evening through the year. When we go to bed, we turn
off the lights and TV. In the average home, 25 percent of all the
electricity we use is for lighting and small appliances, such as TVs, VCRs
and stereos. A good percentage of energy consumed by lighting and
appliances occurs in the evening when families are home. By moving the
clock ahead one hour, we can cut the amount of electricity we consume each

Daylight Saving Time also saves a small amount of energy in the morning
when we rise. Studies show that 70 percent of all Americans rise prior to
7 a.m. during the workweek. During the summer months, sunrise is very
early in the morning, so most people will wake after the sun
rises. Because the sun is up, we will turn on fewer lights in our
homes. Thus, we actually use less energy in the morning.

In the winter, the afternoon Daylight Saving Time advantage is offset by
the morning's need for more lighting. In spring and fall, the advantage is
less than one hour. So, Daylight Saving Time saves energy for lighting in
all seasons of the year except for the four darkest months of winter
(November, December, January and February) when the afternoon advantage is
offset by the need for lighting because of late sunrise.

Daylight Saving Time "makes" the sun "set" one hour later and therefore
reduces the period between sunset and bedtime by one hour. This means that
less electricity would be used for lighting and appliances late in the

We also use less electricity because we are home fewer hours during the
"longer" days of spring and summer. Most people plan outdoor activities in
the extra daylight hours. When we are not at home, we don't turn on the
appliances and lights. 

There is a small public health benefit to Daylight Saving time. Several
studies in the U.S. and Britain have found that daylight, almost certainly
because of improved visibility, substantially decreases (by four
times) the likelihood of pedestrians being killed on the roads. 

On Wed, 21 Feb 2001, Sourav K. Mandal wrote:

> "Eric Crampton <[EMAIL PROTECTED]>" wrote:
> > > I have never understood this rationale--especially for farmers. 
> > - easier to have hired labour show up for 6 instead of 5 am.
> > - the greater the overlap between your work-hours and everyone else's, the
> > easier it is to get parts and repairs and such
> > - if your kids are in school 9-3:30 (and on the bus 8:00-4:30), you can
> > get more work out of them from 4:30 to sundown if sundown is later (tough
> > to get much work out of them before school).
> As valid as these concerns are, would they really affect the national 
> economy?  Since government enforces daylight savings, they have to look 
> at the total cost-benefit analysis.  Agriculture is the only industry 
> that really _needs_ daylight savings, yet it only accounts for a small 
> fraction of the country's GDP.  According to census data for 1997, 
> "Agriculture, forestry, and fishing" only account for $130 billion out 
> of a GDP of over $8 trillion, or only about 1.6% of the entire economy. 
> (
> So why bother?  Agriculture is a strong lobby on capital hill, that's 
> for sure, and farming states do have a disproportionate number of 
> senators ...
> Sourav
> ------------------------------------------------------------
> Sourav K. Mandal
> "... and he wondered whether the peculiar solemnity of
> looking at the sky comes, not from what one contemplates,
> but from that uplift of one's head."
>                        ---- Fountainhead, Rand

Reply via email to