Benjamin Franklin - an inventor, philosopher and American political heavyweight - first proposed the idea in a letter he wrote when in Paris in 1784. In it he joked that Parisians should be roused from their slumbers an hour earlier by ringing church bells and firing cannons in the street.
The idea didn’t actually resurface until 1895, when New Zealand scientist George Vernon Hudson proposed to his government that the clocks should go forward by two hours every summer. He wasn’t successful.
The idea really took off when a builder called William Willett (who just so happens to be the great-great-grandfather of Coldplay frontman Chris Martin) campaigned in Britain to change the clocks.
It’s thought he was annoyed that his golfing would be interrupted by the sun going down
so he wanted to change the law to make sure there would be more light in the evening.
He campaigned for the clocks to change until he died of influenza in March 1915, but it wasn't his love of golf that persuaded Parliament. In the spring of 1916, during World War One, the German army turned the clocks forward as a way of conserving energy. Many (but not all) European governments followed suit shortly afterwards - including the UK.
Opinions are very mixed. Some people say that changing the clocks twice a year upsets the natural rhythm of sleep, which can lead to health problems, such as an increase in the possibility of having a stroke.
However, some say that if the practice was stopped, darker mornings in winter would be more unsafe, for example on the roads. Some industries such as agriculture also rely on there being lots of sunlight available to work in.
In March 2019, the European Parliament voted to end the practice of changing the clocks twice a year, with member states needing to decide whether they would permanently remain on winter or summer time by the end of 2021.
However, the reform has temporarily been put on hold.
There are currently no plans to stop changing the clocks in the UK.
I am in the UK.