Daylight saving time was introduced in Germany during the First World War in 1916, in order to make more efficient use of working hours in the armaments industry, but it was discontinued soon after. While it was briefly reintroduced during World War II, daylight saving time, or Sommerzeit in German, was not adopted permanently in Germany until 1980.
This was a few years later than in other European Union countries, but it meant that West Germany fell into line at the same time as East Germany. The main reason for the time change was given as the "better use of daylight" in the bill presented to parliament.
Experts at the time had calculated that 0.15 percent of energy would be saved, but more recent studies by the Federal Association for Energy and Water Economics (BDEW) have concluded that while fewer lights are switched on in summer evenings, more heating is used in the mornings.
On top of this, the extra daylight has led to more family-based free-time activities, which have also increased energy consumption.
The signal for Germany's switch to and from daylight saving time is broadcast from the National Metrology Institute (PTB) in Braunschweig in Lower Saxony through a broadcaster in Mainflingen near Frankfurt.
This signal, which covers 2,000 kilometres in all directions, controls TV and radio broadcasts, time service of the telephone network Deutsche Telekom, the 120,000 clocks of German rail operator Deutsche Bahn, the time signals in countless factories, as well as many private radio-controlled clocks.