On the last weekend in March the clocks change all over Europe, as happens twice a year, every year. At 02.00 Central European Time (CET) on Sunday, time will leap forward one hour to 03.00 CET, to what is often called summer time. It will end on the last Sunday in October at 03.00 CET when clocks go back one hour to 02.00 CET, reverting to standard time.
The so-called Daylight Saving Time (DST) is designed to make the best use of natural light. Clocks jumping forward in the spring make evening daylight last longer; clocks going back in the autumn mean it is lighter in the mornings when people get up.
What happens in the European Union?
The latest EU Directive on the matter dates from 2001. It stipulates a unified calendar for all 28 member states, so each country introduces summer time and reverts to standard time on the same dates.
The EU says countries began synchronising clock changes in the 1960s and 1970s, and the introduction of the single market made a harmonised approach necessary. Until the early 1990s the UK and Ireland used to put the clocks back in the autumn, a month later than other countries, but since 1996 all nations have adopted common dates.
EU countries are free, however, to choose their particular time zone. Three to the west (Ireland, Portugal and the UK) apply Greenwich Mean Time (GMT), 17 adopt GMT+1, while eight countries to the east implement GMT+2 as their standard time.
Is everybody happy?
No. In fact so many are unhappy that in February the European Parliament voted for an investigation into ending DST. Influenced by a parliamentary study published in October that suggested the practice disrupts the human body-clock, 384 MEPs backed – and 153 voted against – a resolution urging the European Commission to review the arrangements and change the rules if necessary.
What do daylight saving's opponents say?
Opinion is divided on whether the current system works best for northern countries. The proximity to the North Pole for some means they already have plentiful daylight in the summer, while in the winter they are plunged into darkness for all but a few hours every day.
Finland has called for daylight saving to be abandoned across the EU after gathering a petition of more than 70,000 people calling on its government to stop the practice.
In March 2017, Dutch MEP Annie Schreijer-Pierik handed a 20,000-strong petition from the Netherlands to the European transport commissioner calling for an end to the move to summer time.
Others have argued that the practice is harmful elsewhere. French Greens MEP Karima Delli told the recent parliamentary debate that the clock change brings a lack of sleep which endangers road safety.
“It is the cause of a large number of accidents involving the most vulnerable road users,” she said, citing pedestrians and cyclists.
It has also been argued that energy savings – seen originally as a good reason for DST – are negligible, as modern society is using electricity regardless of whether it is light outside or not.
And summer time’s supporters?
Many people throughout Europe enjoy the increased daylight in summer evenings. Belgian MEP Hilde Vautmans told the parliamentary debate that losing summer time would mean losing an hour of light for seven months each year.
“That would mean the end of beautiful summer evenings with friends on the terrace in the garden, of biking or jogging with therefore a lesser quality of life,” she said.
The European Union argues that the main objective of the harmonised approach is to ensure that the internal market works properly. In 2007, a European Commission report underlined the importance of keeping it.
Energy consultants Utilitywise claim that in the UK, weekday demand for power drops sharply in the week after the clock changes to summer time.
Are the rules likely to change?
The Commission has shown little sign it is keen to act on the European Parliament’s call. However it has not rejected the arguments of daylight saving’s opponents out of hand.
Transport Commissioner Violeta Bulc told the parliament that the benefits from longer daylight had to be taken into consideration and suggested there was little appetite in national capitals for change.
She also warned that decisions had to be taken at a European level, and applied throughout the EU in a “synchronised and unified manner”.
“Uncoordinated national time change in the course of the year would create very important problems for the good functioning of our internal market, notably in the transport sector,” she said.