When daylight saving time (DST) was first proposed, its rationale was to save money by taking better advantage of the longer daylight hours from spring to fall. At that time, artificial lighting was the result of candles and oil lamps. Later on, as electricity was used to create artificial lighting, there was a real savings in the electric bill during daylight saving time as lights accounted for the majority of the bill.
These days, lighting accounts for 3 to 4 percent of a household's electricity bill, so the savings are minimal. Also, any savings in lighting bills are more than offset by the fact that most people use the extra daylight to pursue recreational activities, by driving to their destinations and using up precious fossil fuels.
There have been numerous studies done in the last few decades to determine whether the pros of DST actually outweigh the cons. The findings are contradictory.
What is certain is that daylight saving time has several real drawbacks.
When we set our clocks ahead in spring to give us an hour of daylight in the evening, we are also giving ourselves an hour of extra darkness in the early morning. This means that people with fixed daily schedules must do their morning traveling in the dark. Children standing at dark corners waiting for the school bus are at more risk of pedestrian traffic accidents.
People's circadian rhythms are disturbed when the clock is changed. This can be especially upsetting to babies and small children, who cannot be expected to understand the change. Many adults also complain of jet lag like symptoms after changing the clocks. Companies often report a lowering of employee productivity for up to a week after the change each spring and fall. When spread across the nation, this lowering of productivity can be a significant economic loss.
Electronic equipment that uses an internal clock must be adjusted. For the most part, this is merely an annoyance, but when it comes to medical equipment, the annoyance can turn into a serious problem.
One of the biggest drawbacks of DST is that it is not consistent. There are differences in the dates when it begins and ends and there are countries that do not observe it. Even within a country, there can be differences in observance. In the US, for instance, Hawaii and Arizona do not practice DST.
This inconsistency causes major problems for public transit companies, especially airlines and long distance trains and buses. It is a scheduling nightmare when the originating city is on DST and the destination is not, or vice versa.
These drawbacks must be taken into consideration when deciding whether or not daylight saving time is worth the effort.