When do hours change

Visit the Royal Observatory. Planetarium shows and events. Out of this world stargazing and astronomy shows for the whole family. See what's on. Stand on the Prime Meridian Line. Why do the clocks change? Discover gifts from the home of time Shop. How old is Earth? How fast can you think? How long is a light year and how short is a femtosecond? What does Greenwich Mean Time mean?

Can you tell the time with flowers? When did time begin? This light-hearted, illustrated miscellany from Royal Observatory Greenwich goes a long way to answering some of these questions and also presents a whole range of other amazing facts and figures which show the influence of time on our daily lives Buy Now.

A stylish hour analogue clock that will make a statement on any wall, with its bold monochrome face, and matte black metal casing Detail of Harrison's marine timekeeper H4. Not every state follows daylight saving time, however. Hawaii and most of Arizona opt out. Indiana did not observe DST until Because the state had two time zones, some of its counties changed their clocks in the fall and in the spring and some didn't.

Because time zones were difficult to keep track of, a bill was passed in to unify the practice throughout the state. But the law was controversial, and it made the governor at the time, Mitch Daniels, unpopular.

Benjamin Franklin is often credited with first proposing daylight saving in his essay "An Economical Project. Daylight saving time was first enacted by the federal government during World War I as a way to conserve coal. Daylight saving time persisted in various forms on local and state levels until the federal government passed the Uniform Time Act in Last year, the American Academy of Sleep Medicine released a statement saying public health and safety would benefit from eliminating daylight saving time.

Keep track of time with Royal Observatory Greenwich watches, and our famous Shepherd Gate clock, reproduced for your wall at home.

When do the clocks go back? Why do we change the clocks? What is Greenwich Mean Time - and why does it matter? Will I lose or gain an hour in bed?

Why do the clocks change? Visit the home of time Stand on the historic Meridian Line and see Harrison's ground-breaking time keepers at the Royal Observatory Visit now. What are the arguments for and against changing the clocks? He was inspired by the relationship between human methods of marking time such as BST and astronomical phenomena: "I set out to explore what actually happens during that hour when the clocks "spring forward" to begin British Summer Time.

Why do the clocks change at the weekend? Visit us. Royal Observatory. Plan your visit. Top things to do. Discover gifts from the home of time Keep track of time with Royal Observatory Greenwich watches, and our famous Shepherd Gate clock, reproduced for your wall at home Shop.

How old is Earth? How fast can you think? How long is a light year and how short is a femtosecond? What does Greenwich Mean Time mean?