It's Summertime again!

Summer time is approaching again. That means the clock moves forward an hour and the days feel longer. Although many devices adjust the time automatically these days, it is still useful to know when this happens and why we actually change the clock. Summer time begins every year during the last weekend of March. In 2026, the clock will be changed on Sunday, March 29 , at 2:00 AM. The clock will then move forward an hour to 3:00 AM. That means you will have missed 1 hour of sleep on Sunday. Are you fit enough not to notice the hour short, or will your biorhythm be affected for days? Approximately 70 countries change the clock twice a year. In the European Union, summer time runs from the last Sunday of March to the last Sunday of October. Do you know the story of Summer Time?

Origin

In antiquity, the daily rhythm was flexibly adapted to the length of the day. For instance, for the Romans, the day began at sunrise and ended at sunset. That day was divided into twelve hours, and thus the hours were shorter in winter than in summer. However, when the length of an hour was fixed at sixty minutes in the Middle Ages, a difference in sunshine hours arose between summer and winter.

It has sometimes been claimed that summer time was first proposed by Benjamin Franklin in an anonymous letter to the editors of the Journal of Paris. However, the article was intended as a joke, and moreover, Franklin did not propose introducing summer time, but rather that people should get up and go to bed earlier in the summer to save on candles. Benjamin Franklin (1706–1790) was one of the Founding Fathers of the United States. He was also an American politician, scientist, and moralist. He is the epitome of industriousness and honesty.

The first serious proposal came from the New Zealander George Vernon Hudson in 1895, who wanted to adjust time to the rhythm of man rather than the other way around. He therefore wanted to set the clock forward two hours in the summer. The Englishman William Willett came up with a similar proposal in his *Waste of Daylight* from 1907, but he was unable to get it done by the British government, despite support from a significant group of Members of Parliament.

 

History

The first practical application of summer time was by the German Empire during the First World War, starting on April 30, 1916. Summer time was also implemented in the occupied territories. Although the Netherlands was neutral, it also introduced summer time a day later (May 1). The United Kingdom followed on May 21. This first summer time ran until October 1, 1916.

The United States Congress introduced various time zones on March 19, 1918 (which had already been in use by the railroads since 1883) and made summer time official (effective March 31) for the remainder of the First World War. Between the two world wars and also during the Second World War, summer time was in use in various European countries (including the Netherlands).

The 1973 oil crisis, which led to a wave of energy-saving measures, prompted many European countries to reintroduce summer time. Spain and Albania started doing so in 1974. Greece and Cyprus followed in 1975. France followed in 1976, the Netherlands, Belgium, Luxembourg, Portugal, and Poland in 1977, and Czechoslovakia, Bulgaria, and Romania in 1979. West Germany waited until 1980, until an agreement had been reached with East Germany. Austria, Denmark, Hungary, Norway, and Sweden also joined at that time. The Soviet Union, Finland, Switzerland, and Liechtenstein followed in 1981, and Yugoslavia in 1983. The last country in Europe to decide to join was Andorra in 1985. The only European countries that do not use summer time are: Armenia, Azerbaijan, Georgia, Iceland, Russia, Turkey, and Belarus.

 

Clarity of time indication

During the transition from summer time to winter time, there are nominal times, each referring to two real times. To avoid ambiguity, it is advisable to state in relevant cases whether it concerns summer time or winter time. This is mandatory in Dutch official documents. The Act on Further Regulation of Statutory Time formulates this as follows: When any official document contains a time indication relating to the last hour of the [summer time] period, the time indication shall state that it concerns Central European Summer Time.

If the application or non-application of summer time forms part of the time reckoning, the time reckoning changes twice a year and the stated entry is that of the applied time reckoning. If the summer time system forms part of the time reckoning, the time reckoning changes only when the system is changed. The stated entry is then part of the time indication within a non-changing time reckoning.

 

The Netherlands

Summer time is not always introduced on the same date:

• 1916–1939: different rules were applied for determining the duration of summer time, as is evident from the annual publications in the Official Gazette. The earliest start date was March 26 (in 1922), the latest end date October 8 (in 1922, 1933, and 1939).
• 1940-1942: Uninterrupted Summer Time from May 16, 1940, to November 2, 1942. In 1940, the switch from Amsterdam Time to Central European Time also took place by order of the German occupying forces. During this time, it did not get light until around 9:30 AM in the winter. In the evening, however, it remained light until 6:00 PM.
• 1943: summer time from March 29 to October 4
• 1944: summer time from April 3 to October 2
• 1945: summer time from April 2 to September 16
• 1946-1976: no summer time
• 1977-1980: Summer time runs from the first Sunday of April to the last Sunday before October 2. The earliest start date was April 1 (in 1979), the latest end date October 1 (in 1978).
• Since 1981, the rules as laid down in a directive of the European Union have applied.

The Act on the Further Regulation of Statutory Time has been in force since March 24, 1977. This makes it possible to establish summer time. The Decree of December 5, 2001, establishing summer time, has regulated summer time since 2002.

In the summer, the sun rises so early that it is already light while most people are still asleep. By changing the clock, the sun appears to rise and set later. As a result, according to the clock, it remains dark longer in the morning and light longer in the evening. This aligns the period of daylight better with the period when most people are awake. The idea behind summer time is that it would allow for savings on (electric) lighting. However, the energy-saving effect of summer time is controversial.

 

Belgium

During the First World War, Germany also introduced Summer Time in occupied Belgium starting April 30, 1916. From 1919 until early 1940, Summer Time was introduced annually in Belgium on irregular dates. The Royal Decree of September 15, 1928, established that Summer Time began each year at 2 a.m. on the night of the 2nd or 3rd Saturday to Sunday of April, and ended at 3 a.m. on the night of the 1st Saturday to Sunday of October. In May 1940, the clock, which had already switched to Summer Time, was moved forward another hour by order of the German occupying forces: previously, the clock in Belgium ran on Greenwich Mean Time (UTC / GMT), and from that moment on, on Central European Time (CET). Summer time, which began in 1940, ran until the end of 1942. From 1943 through 1946, and subsequently since 1977, Belgium has used summer time.