For people who don't know what DST is, I thought this may help out if you're curious.
The idea was brought before the very end of the 19th century and implemented exactly a 100 years ago. Primarily it was to save power on lights, thus it extended the daylight by exactly one hour. It made it more useful having the sun an extra hour in the evening than very early in the morning (early as in, already day at 4 am for some countries).
However, the days of only a few households being able to afford electricity are long gone and cities can easily be kept illuminated regardless of time. So despite the fact that we all love seeing sun at 9~10 pm during summer breaks, it still brings a question.
So the question goes again.
Why? Myths say because of farmers, which is false, they actually oppose it. It's because big companies would complain, the very states/countries themselves might as well. Researches have shown that DST boosts gasoline consumptions and money flow in many other businesses as well.
(Which equals more money into the budget thanks to taxes)
No one is more aware of that than gas stations, which is why the Association for Convenience and Fuel Retailing, a lobbying group for convenience stores, has pushed to start daylight saving time earlier in the year. In 2010, Jeff Miller, the group’s chairman at the time, said the industry had added an estimated $1 billion in annual sales since the organization lobbied to add a month to daylight saving in 1986.
“That’s tens of billions of dollars in sales since then,” he said in a news release
Source: Wikipedia, newspapers, various websites, my own DST research