At the end of March and the end of October, generally on a Sunday, the clocks will change and one day in the year will be 23 hours and another will be 25 hours.
In 2021, the clocks went forward to British Summer Time on 28th March and back to Greenwich Mean Time on 31st October. Many contemporary clocks will do this automatically.
This happens due to a system known as Daylight Savings Time, which is used in most of the western world, as well as some parts of South American and Oceania, although it is not used by countries near the Equator, and has seldom been used in South East Asia.
The notion of standardised time consisting of 24 equally divided hours is relatively new, and up until the Industrial Revolution, most towns and cities, let alone countries, kept their own time and set their own clocks.
The genesis of this change came in a satirical letter sent by American inventor Benjamin Franklin in 1784, which suggested that the people of Paris could save money if they woke up earlier and used sunlight instead.
It went further to suggest that candles should be rationed, window shutters taxed and church bells and cannons fired to ensure that everyone was awake.
He did not necessarily propose daylight saving time or any kind of standardised time, but he planted the seed of an idea that would eventually be proposed over a century later.
George Hudson, an entomologist who loved to collect insects, wanted more daylight after his working hours were done to follow his passion, and so he proposed a shift of two hours during the summer.
At the same time, William Willett, a British builder and golfer proposed a similar idea in 1905, which was first presented to Parliament in 1908 by Robert Pearce MP.
That same year, Port Arthur, Ontario became the first city in the world to adopt Daylight Savings Time, and during the First World War, nearly every combatant adopted it as a way to save fuel during the night.
This would see it be adopted and used again in the 1970s as the result of an energy crisis, and since then Europe and the United States have never looked back.