Summer time is the aberration, not winter time. Don't be too quick to think it is just a few wimpy farmers in Scotland who don't want to get up in the dark, either. There is a gradual lessening of winter light across the whole of the UK, from south to north, and a variation all year in sunrise and sunset from East to west.
Every year it is evident that many people don't know that the further north you go, the shorter the winter daylight is, and the further west you go, the later the sun rises.
It is not just a matter of the clocks being an hour earlier or later, the whole day from sunrise to sunset is shorter, and the sun in lower in the sky, so gives less light.
Sunrise on Dec 22
London - 08:04am
Glasgow - 08:46am
Daylight hours on Dec 22nd
Plymouth - 08:01 hours
Manchester - 07:28 hours
Edinburgh - 06:57 hours
Wick - 06:20 hours
Sunlight quality on Dec 22nd
"In the summer it doesn’t really matter where you are in the UK in terms of the potential daily radiation because although the intensity may be less in the north, this is compensated by a longer daylength. It is when you come to the winter that it gets worse, if you are living in Shetland. In the winter, whereas we have got about 8 MJ/m2 of radiation at the edge of the atmosphere in Penzance, it decreases to about 2 in Shetland. So if you are suffering from SAD it could make a big difference where you live in the UK.
"There are important geographical differences in the amount of cloud cover, so comparing similar sorts of latitude, if you are on the Essex coast you might be expecting an annual average about 4 hours of sunshine per day whilst in the Welsh mountains you will be receiving on average 1 hour per day less sunshine. And if you live in the Scottish Highlands then you would lose another hour’s sunshine a day on average (Met Office, 2009)."
www.google.co.uk/?gws_rd=ssl#q=Sunlight+quality+latitude