Hour change causes a stir

An extra hour for many, but irksome for some

By John Duce of BBC Science

Clocks change by an hour on Saturday night in many parts of the world to mark the end of so-called "daylight saving time" in the northern hemisphere, and the start of summer in the south.

But despite its widespread adoption, this enforced time change still creates controversy around the globe.

The American inventor and politician, Benjamin Franklin, first came up with the idea of daylight saving time in 1784.

What would Mr Franklin have made of this daylight pursuit?

He noted that people were wasting daylight hours on summer mornings by lying in bed and that if clocks were put forward then there would be more light in the evenings when people would be around to enjoy it.

Germany was the first country to formally introduce the idea in 1915 to cut lighting and energy costs by having longer summer evenings.

Since then the system has been adopted by about 70 countries around the world, mainly in Europe and North America.

Protests

But such a seemingly innocuous issue still arouses strong passions.

Last year in Mexico the imposition of daylight saving time sparked political protests, the issue being seen as overbearing central government imposing its will on the country.

In the United States, parts of the state of Indiana do not recognise the system as farmers say they get up when the sun rises and the time changes are simply an administrative nuisance.

Arizona has also refused to adopt the system.

Countries on or near the equator are mainly spared such bickering - they have a fairly constant number of daylight hours throughout the year.

So there is no need to tinker with the clock to make sure people are up and about to enjoy their time in the sun.