Daylight-saving time / Wer hat an der Uhr gedreht?

As many of you know, the time differnce between Toronto, Canada and Germany is usually 6 hours, but for some weeks it is 7 hours. Why is that?

Wikipedia tells the truth about Daylight saving time:

"Daylight saving time (DST), often referred to as daylight savings time, is a widely used system of adjusting the official local time forward, usually one hour, from its official winter standard time for the duration of the spring and summer months.

Governments often tout it as an energy conservation measure, on the grounds that it allows more effective use of natural sunlight resource in summer time. (People go to bed and wake up earlier, which reduces use of electric lights.) Some opponents reject this argument.

Europeans commonly refer to the system as summer time. All countries in Europe but Iceland observe daylight-saving time and change on the same date and time: moving clocks forward one hour on the last Sunday in March and back one hour on the last Sunday in October.

In Canada, time is under provincial and territorial jurisdiction, not federal. The governments of Ontario, British Columbia, Manitoba, Quebec, Prince Edward Island, New Brunswick and Alberta have pledged to change their daylight saving rules to match the new U.S. rules.

In 2007, their DST will start on the second Sunday of March, and return to standard time on the first Sunday in November. The remaining provinces and territories will continue to change time on the first Sunday of April and last Sunday of October unless they change their legislation."

Any questions? ;)