Between 27 October 1968 and 31 October 1971, the UK was on British Standard Time which was basically British Summer Time (GMT/UTC +1) all year round. This was done largely at the insistence of road safety campaigners. The statistics showed a slight increase in morning accidents and a substantial decrease in late afternoon/evening ones. However, it was later discovered that a large part of the reduction in evening accidents was due to the concurrent introduction and enforcement of drink-driving laws.

But the experiment was abandoned not so much because of statistics as because of the outcry of mothers who did not want to send their children to school in the dark. There were reasons for this.

Back then the majority of Primary School (5-11) children walked to school. In those pre-global warming days that meant negotiating fog, frost, ice and snow almost every day in winter. Being dark just made it worse!

Standard winter wear for kids back then was the black or charcoal grey hooded dufflecoat, which made the kids harder to see, even with the hi-vis orange armbands the schools sold at a shilling a pop!

Most importantly, Infants Schools (5-8) back then closed at half past three in the afternoon. Even in the dead of winter, the youngest kids could, on GMT, walk to and from school in broad daylight. Junior schools closed at four, meaning those kids got home in near-daylight as well.

Basically, Mums wanted their kids, especially the youngest, home before dark, and they didn't want them leaving home until it was light!

As to biological rhythms, our bodies are still attuned to Central African patterns of daylight and season. It's going to take another million years or so to change that! European skins only started to lighten a few thousand years ago, after all!