Benjamin Franklin is credited with advancing the concept of daylight-saving time. He wanted to save candle consuming, therefore in 1784 he wrote a paper expressing the virtues of extending daylight. William Willett was actually the one who invented DST in 1905. As always, the world "wasn't ready"; Germany, and its allies were the first to use DST some 10 years later.
The thing is, one hour won't conserve much energy. People should learn that computers turned on and do nothing costs money to the person paying electricity and just reduces the world's energy reserves. TheRegister.com has several articles about it (and company green scores too!). I quote an article:
After all, research from 1E, the software company that developed the NightWatchman software, has found that computers left on overnight are responsible for the emission of around 700,000 tonnes of CO2 every year.
You can see a list of countries/capital cities and their time here - it also displays detail DST events as well as other time/date/temperature interesting data. Also, checkout some energy conservation tips.