Go to content
Logo of Bundesnetzagentur

Hint: This website is not optimized for your browser version.

How changing the clock is processed in SMARD data


On Sunday we change our clocks from daylight saving time to standard time. This is also reflected in a particular way in the time series.

Early Sunday in Germany, clocks will be changed from daylight saving time to standard time and Germany will then be back on Central European Standard Time.

Every year on the last Sunday in October clocks are put back from 3am to 2am. The time change is also visible in the time series because all time data on SMARD refer to the Central European Time that is being observed when the data are recorded.

Example: 2020 actual consumption time series

Change to daylight saving time

Change to standard time

29 March 2020, 1:30am-1:45am

10,291 MWh

25 October 2020, 2:30am-2:45am

10,496 MWh

29 March 2020, 1:45am-2:00am

8,401 MWh

25 October 2020, 2:45am-3:00am

10,461 MWh

29 March 2020, 3:00am-3:15am

10,200 MWh

25 October 2020, 2:00am-2:15am

10,478 MWh

29 March 2020, 3:15am-3:30am

10,291 MWh

25 October 2020, 2:15am-2:30am

10,460 MWh

This means that every year on the last Sunday in March when we switch from standard time to daylight saving time, the hour from 2:00am to 3:00am is skipped. Then, when we change from daylight saving time to standard time, the hour from 2:00am to 3:00am is repeated. This is the case when data categories are displayed in quarter hour resolution (eg actual electricity consumption) and also when they are displayed in hour resolution (eg wholesale prices).


Germany has been observing daylight saving time since 1980 after an oil crisis led to energy-saving measures. The idea was that daylight saving means it would remain lighter in the evening longer in summer and so people would not turn on lights at home until later and thus less energy would be consumed.

Back to news archive