When is the time change in March?

The change from winter time to summer time will take place in the early hours of 26th March.

Why do we change the clocks?

Since ancient times, different civilisations modified their activity according to the sun, dividing the day into periods of approximately twelve hours, better known as temporal hours. This system, based on the hours of sunlight, continued until the 14^th century, when the first mechanical clocks were built, and therefore the days were adapted, as accurately as possible, to 24 hours. This is how the fixed hour system arose.

Who suggested the time change?

Benjamin Franklin, American politician and researcher into electric energy, whose motto was “early to bed and early to rise makes a man healthy, wealthy and wise”, observed that when he got up early he exploited more hours of sunlight and therefore the saving in electricity was significant. Many of his studies and publications dealt with how to exploit daylight better and how to save power. But these writings did not make an impression on the population as there was no set timetable for anything.

When were the changes in time zones implemented?

It would not be until the coming of the railways, at the end of the 19^th century and beginning of the 20^th, when timetables as we know them today were established.

It was the British builder William Willet who reached the same conclusions as Benjamin Franklin when riding his horse one day at dawn. Most of the shutters of the houses were closed at that early hour, which was a waste of electricity for the houses in England. This concern led him to publish numerous studies, but his theories were not applied until the First World War.

Summer time was applied for the first time on 30^th April 1916. The first countries to apply it were Germany, its allies and occupied territory. Later it was the United Kingdom and the rest of the countries at war, and one year after that, Russia. The United States, for their part, did not implement it until 1918.

In the Second World War, the United States required the use of summer time with the intention of saving energy in war zones. It was also thus established during the 1973 oil embargo.

The implementation of summer time in Spain is laden with curiosities. It was not until the 20th century that the time was marked by the Greenwich Meridian (GMT). Before that, the official time was marked by the Madrid Meridian, and each province had a different local time according to its location. It was on 15th April 1918 that summer time was officially established. Time-related chaos arrived with the Civil War; the Republicans added an hour to GMT, and the Franco-held zone added an hour to 26th March only. Neither did the end of the war solve the problem of the clocks; Republican Spain added another hour to the Greenwich Meridian. Besides, summer time was not applied in 1920, 1921, 1922, 1923, 1925, from 1930 to 1936, 1941, 1947, 1948 and the period between 1950 and 1973.

Nowadays, the change from summer time to winter time is applied in most states in North America, in the areas of Bermuda, the Bahamas and Cuba, some South American, Asian and African countries, the great majority of Europe and areas of the Pacific such as Australia and New Zealand..

How much do we really save on our electricity bill?

By moving the clock back or forward according to it being summer or winter, respectively, we attempt to exploit the natural sunlight as much as possible, as an energy efficiency and savings measure. From Franklin’s or Willet’s first studies it seems obvious that if we use all the hours of natural light, there must be an energy saving, but do we really save on our electricity bill?

Lately there have been protests questioning the alleged saving obtained with the time changes, but there are studies that insist on the need to continue to change the hands of our clocks.

In 1975, the United States Department of Transport concluded that consumption can be reduced by 1% during March and April, coinciding with summer time. In another study from 2011 it was stated that 1.3 terawatts of electricity were saved in comparison with the previous year. This would mean that the annual consumption of electricity was reduced by 0.03%.

That same year 2011, in Spain, the Institute for Energy Saving and Diversification (Instituto para la Diversificación y Ahorro de la Energía, IDAE) advocated an energy saving of 5% during summer time, entailing a reduction of 6 euros on the electricity bills of 90 million homes. And they state that in spite of the fact that these percentages may appear small, they could represent a significant saving on the electricity bill with regard to the total use of power in a country. Besides, the saving is apparently greater in some regions than in others, mainly in the countries further north.

But the opposite opinion comes from environmental associations and other studies that conclude that this alleged saving is not so significant, because more electricity is consumed during the evenings and these changes are detrimental to the health and can even reduce productivity at work.

It seems that there is no clear opinion in this regard. Besides, in order to confirm a saving of energy, it would be necessary to consider a series of factors that aid energy saving, such as the new technologies applied to lighting, the more efficient use of power in businesses and homes, or the climate and temperature in each area.