Do you know why we put the clocks forwards and backwards by an hour during the year?

In the UK, Daylight Saving Time came into use in 1916, due to the costs of energy usage during the first World War. The annual hourly changing of the clock was first established in the UK more than 100 years ago under the Summer Time Act 1916, with the thought that lighter evenings might preserve fuel for the war effort.

However, it was Canada that became the first country to implement Daylight Saving Time, in 1908. The US followed suit in 1918.

All European Union countries and many European non-members continue to make the switch twice a year. Outside of Europe the United States and Canada, changing the clocks is also practiced in Paraguay, Chile, Cuba, Haiti, the Levant, New Zealand and parts of Australia.

But why do we change the clocks at all? Is it for scientific reasons, possibly to do with the positioning of the Sun in summer and winter?

In a word, no. The idea was first entertained because some people thought that by sleeping through daylight in the summer, the day was being wasted.

We change the clocks to make better use of natural daylight in the morning. During the summer time, we borrow an hour of daylight from the morning and shift it to the evening to reduce our energy consumption.

During the winter solstice, just before Christmas, we get less than eight hours of sunlight. If we didn’t put the clocks back, sunrise would be after 9.00am and sunset before 5.00pm. By putting the clocks back, it’s still dark when we’re going home from work, but the morning commute is a bit lighter.

British Summer time (BST), sometimes called Daylight Saving Time (DST), is a period in summer when the clocks go forward by one hour, meaning we start our day earlier and see more sunlight. In October, the clocks go back again for the winter months.

Opinions of this process 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, others say that if the practice was stopped, darker mornings in winter would be more unsafe, for example on the dark and potentially icy 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.