British Summer Time runs from the last Sunday in March to the last Sunday in October. In the depths of winter the nights in the UK are anything from 15-19 hours long. Longer nights mean frost and fog are more likely to form. Twice a year the clocks change, forward in the spring and then back again in the autumn. But why? It happens twice a year. We all change our clocks and watches by one hour. In the spring, we add an hour, and go onto what is called British Summer Time, while in the autumn, we do the reverse, and return to Greenwich Mean Time. Why bother? It's all to do with saving the hours of daylight, and was started by a guy called William Willett, a London builder, who lived in Petts Wood in Kent. Basically, he figured that you could improve the population's health and happiness by putting forward the clocks by twenty minutes every Sunday in April and do the opposite in September. Economics His idea was not taken up, even though a "Daylight Saving Bill" was introduced some five years before the outbreak of World War One. But once the war started, it was considered wise to economics, to promote greater efficiency in using daylight hours, and in the use of artificial lighting. And so in 1916, "Daylight Saving Time" was introduced. Even though most countries abandoned this after that war, some eventually decided that it was a good idea, and most of these nations began to keep it throughout the year. Experiment Since 1972, Britain has decided to go with Greenwich Mean Time in winter, and British Summer Time in Summer. But back in 1968, Britain tried a four-year experiment by advancing time one hour ahead of GMT throughout the year. But those living further north, particularly in Scotland, found it most unsatisfactory, with dark mornings for much of the year, and the experiment was dropped. Why some countries decide to change the clocks after World War One?
To improve the people's health and happiness. To do a certain experiment To save energy to develop economies. All of the above.