The Lies: Why Daylight Savings gets it Wrong

“Daylight Savings” is a lie.

OK, maybe that’s a bit harsh – its supporters don’t generally claim that they are really “saving” daylight, just making more productive use of it. But they’re still not telling the whole truth. They claim that lives will be saved, jobs created, energy bills reduced if we change the clocks; what they neglect to mention is that it’s not the clocks that make a difference, it’s us getting up earlier.

In a nutshell, to make best use of the extra daylight of summer, you have to get up a bit earlier, to catch the dawn. But, the theory goes, schools and offices all open at about 9AM, all year round, so this extra light is “wasted” because people aren’t going to get up early if they don’t have to. So instead of persuading people to get up earlier, we trick people into getting up earlier, by making them change their clocks. Since the clock still says 9AM when they get to the office, people think they’re working the same hours all year round.

This kind of paternalistic control might have made sense in the 19th century, where everyone knew their place, but it seems remarkably quaint in the 21st, where every politician is espousing some variation of personal choice and responsibility. Why should the government get to decide when we start work? What’s next? Maximising efficiency by making an hour last longer in the morning than the evening?

More to the point, why does everyone have to get up at the same time anyway? Advocates produce all sorts of pretty graphs showing how more people would be awake in daylight under their proposed schemes, and make it look like the daylight is moving. Why does nobody ask if people’s waking hours could move instead?

Artificial time

There is another lie which advocates slip in as well: that shifting time zones is no more artificial than the creation of Standard Time in the first place. Dividing the day into 24 “hours” is certainly pretty arbitrary, and the shadow on a sundial wouldn’t suddenly jump by an hour when you walked across the 15th line of latitude.

But days are real, and you really can measure the point when the sun reaches its highest point in the sky. We call this noon, or midday. Apparently, this can vary by as much as quarter of an hour one way or the other over the year, but if you take the average, you get something called “mean time”. And if you take the average in Greenwich, you get Greenwich Mean Time. So, not all that artificial then.

Just to be clear, under the “Double Summer Time” part of SDST, Greenwich would see noon at about 2PM. Under GMT, the latest it could get would be 12:15. [1] A glance at a timezone map suggests that the furthest point west in the UK probably sees noon about half an hour after Greenwich, but that’s hardly an excuse to push noon back to 2:30PM. If you have lunch at 1PM BST, you are having a midday meal; in the same way, if you have dinner at 10PM on your summer holiday to Spain, it’s only 8 hours since noon – they’re on the same offset from natural time proposed by SDST.

Footnotes   [ + ]

1. A glance at a timezone map suggests that the furthest point west in the UK probably sees noon about half an hour after Greenwich, but that’s hardly an excuse to push noon back to 2:30PM.

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