GMT is British. Greenwich Mean Time and every other country in the world gets their time from us.
On December 21st every year we get 7 hours of daylight, so it is either darker in the morning or darker in the evening. We don't 'gain' anything.
Do these people actually read the directives before commentating?
Taken directly from the article.
Member states should themselves decide whether their citizens live in summer or winter time.
We changed to BST and didn't change back to GMT which made it far worse. It was still dark at 9am in the northern part of the country, and in Scotland.
Leaving the clocks at GMT would be slightly different.