Ok. Stand back. Let me explain. The hour shift only actually makes a difference for eight weeks a year.
What??? You all say.
Let me explain. Be careful now, this will involve science.
In the UK, the times of sunrise and sunset change by about 15 minutes a week or about an hour a month. So though we have a big jump this weekend when the clocks change, all that’s happened is that we’ve shifted Sunrise a month to when it was at the end of September, and shifted Sunset a month to when it would be at the end of November. There’s nothing in the clock change in October that we haven’t already had or wouldn’t have in a month’s time anyway. It doesn’t make the daylight hours any shorter, though to listen to the grumpiness and ill-informed comments at this time of year, it seems that is what people think.
With me so far?
So the eight weeks which have sunset and sunrise times which we wouldn’t otherwise have are from Nov 22nd to Jan 22nd or so – ie a month either side of the winter solstice.
So here are the sunrise and sunset times and the length of the day for 21st Nov, 21st Dec and 21st Jan for London
Sunrise | Sunset | Daylight hours |
07:29 | 16:03 | 08:34 |
08:03 | 15:53 | 07:49 |
07:53 | 16:30 | 08:37 |
Without the clocks changing, these numbers would be
Sunrise | Sunset | Daylight hours |
08:29 | 17:03 | 08:34 |
09:03 | 16:53 | 07:49 |
08:53 | 17:30 | 08:37 |
I don’t know about you, but 9:03 is pretty late for sunrise and I hate actually going to work in the dark. So to my mind the clock change is worth it for those two months at least.
But guess what – even with the clocks changing, here in Edinburgh I do have to go to work in the dark.
Even though Edinburgh is only about half way up the UK, that is sufficiently further up the planet for those numbers to be inaccurate. In January and November the daylight hours in Edinburgh are about 40 minutes shorter than daylight hours in London. and by December they’re about 50 minutes shorter. (Though of course, our daylight hours are longer by the same amount in midsummer).
So here are the sunrise and sunset times and the length of the daylight hours for 21st Nov, 21st Dec and 21st Jan for Edinburgh:
Sunrise | Sunset | Daylight hours |
08:02 | 15:55 | 07:53 |
08:42 | 15:40 | 06:57 |
08:25 | 16:23 | 07:57 |
Without the clocks changing, these would be:
Sunrise | Sunset | Daylight hours |
09:02 | 16:55 | 07:53 |
09:42 | 16:40 | 06:57 |
09:25 | 17:23 | 07:57 |
If it sucks when it’s dark at twenty to nine in the morning, it REALLY SUCKS if it’s still dark at twenty to ten! (I spent a couple of winters in Sweden – I know).
As I said, the specific eight week period between 22 Nov and 22 Jan are the only time when the sun rises at times it wouldn’t if we didn’t change the clocks.
I hope this helps explain
- why it’s not that much of a deal
- why you’d miss it in December if the clocks didn’t change and
- why I’d REALLY HATE YOU if they didn’t
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