Daylight Saving Time (DST) has been used for more than 100 years. But do its pros really outweigh its impact
DST changes: Dates and local time Longer Evenings
Setting the clocks forward one hour in spring does not create more daylight, but it does change the time (on the clock) the Sun rises and sets. So, when we spring forward an hour in spring, we add one hour of natural daylight to our afternoon schedule
Doesn't Save Energy
A century ago, when DST was introduced, more daylight was a good thing because it meant less use of artificial light and more energy savings. Modern society, with its computers, TV-screens, and air conditioning units, uses more energy, no matter if the Sun is up or not. Today, the amount of energy saved from DST is negligible.
One of the aims of DST is to make sure that people's active hours coincide with daylight hours so that less artificial light is needed. This makes less sense close to the equator, where the amount of daylight does not vary much in a year, or near the poles, where the difference between winter and summer daylight hours is very large.
However, at latitudes between these extremes, adjusting daily routines to the shifting day length during summer may indeed help to save energy. A German analysis of 44 studies on energy use and DST found a positive relationship between latitude and energy savings.
: Can Make People Sick
Changing the time, even if it is only by one hour, disrupts our body clocks or circadian rhythm. For most people, the resulting tiredness is simply an inconvenience.
: Lighter = Safer
Safety is one of the more solid arguments for keeping the lighter evenings of DST.
Studies have found that DST contributes to improved road safety by reducing pedestrian fatalities by 13% during dawn and dusk hours.
Another study found a 7% decrease in robberies following the spring shift to DST.
Con: Costs Money
It is hard to determine the economic cost of the collective tiredness caused by DST, but studies have found a decrease in productivity after the spring
