Introducing “British Economic Time” aka “Sunrise Time” – the ultimate #astronomy geek timezone /ht @fanf

I’m ranting about this on Facebook so I might as well share the amusement.

Generally twice a year on the Today programme you’ll get a package or programme segment about “the clocks are going forwards/back” and how some organisation, charity, peer or MP is proposing to move to “double daylight savings time”.

“Stay on summer time throughout winter”, they say, “and add another hour next summer”.

“Childrens’ lives” will be saved, they say.

“Save energy”, they say.

They’re lying – or rather they aren’t interested in either of those really.

So this is now/again being discussed in a campaign on Facebook and though I respect the participants opinions I have written this:

Amongst the many reasons not to “StayInSummer” is that it means children in Edinburgh will go to school in the dark as sunrise will be after 9am. It’s a potty attempt to synchronise the UK with a meridian which goes through Frankfurt (let alone Paris) and more pointedly hopes primarily to boost retail revenue by providing more “daylight shopping hours” in actual summer by swapping to CET.

I am an astronomer, I like the idea that the concept of “noon” at least approximates to the sun being at its highest in the sky. a 1-hour BST shift is at least plausible for reasons outlined by Franklin and others.

Shifting the country 15 degrees eastwards in pursuit of profit is deeply unromantic, and to do so by laundering it with apparent social benefits is crass.

ps: the financial dividends are also far from certain; similar were expected from George W Bush’s widening of daylight savings time a few years ago, but corrected net energy consumption has increased, it is assumed because the heavier use of domestic heating at the extreme ends of the DST period.

Which lays out my position; I find it dishonest and risible that the proponents of “Double Daylight Savings” can’t just say “Let’s move the UK onto Central European Time” – but such frankness would kill the proposal outright so they’re probably quite wise not to do so.

Several years ago while thinking of something fun to do about this whole issue, I created the idea of British Economic Time:

The concept of BET is very simple: pick a point somewhere (eg: Greenwich) with a fixed latitude and longitude, then define 8:00am to be sunrise at that location for any given day, and “midnight” / zero-hour to be 8 hours before that.

This means of course that certain days will have more than 24 hours, and others will have less than 24 hours, but we have the Internet now so all that will fall out in the wash.

Also: anyone above the Arctic Circle will have to sort themselves out, but that’s no more presumptuous than saying Scotland can/should have its own timezone.

The benefits are huger than DDST – consistent light levels around 8am, safe children walking to school, and a near-theoretical-limit maximum number of retail hours for buying to take place in the hope that that somehow will stimulate the economy.

We can also implement a standard British National Breakfast and a British National Bedtime – sponsored by Transco – to minimise impact upon the National Grid.

I have been pursuing this idea for several years and have implemented it in Python to prototype, and at some point will make it into an app.

If this sounds flippant then yes, actually, it is; it’s an exercise to demonstrate how arbitrary (and somewhat statist) time-measurement is – although I have really implemented the prototype and will eventually do the app.

It’s not actually all that unprecedented, though; pre-railways several local time systems existed, either based around a local meridian (eg: Bristol for the West Country) or the simpler technique of declaring sunrise to be 6am, sunset to be 6pm, noon/midnight bisecting those, and have 12 “hours” of variable length between sunrise and sunset; hence the importance of church clocks/bells to the communities.

When I rant about this – as I do – the takehome I want people to realise is that time *is* arbitrary – where I grew up there was a different school timetable in winter from summer, to compensate for darkness and for the frequent foot-deep snows causing school closure; we had extra time added to the schoolday in summer to compensate. The school fitted around the clock, not vice-versa.

Messing with the clock is a blunt and in the end fairly pointless hammer; the nails are peoples’ behaviour and the regulations that force THEM to live life to an unyielding clock, not the tyranny of the clock itself.

Back in 2009 I discovered Tony Finch (@fanf) who independently had come up with largely the same idea:

The essence of sunrise time is that we reset our clocks each day (by slightly adjusting their timezone) to a fixed time when the sun rises at a benchmark location. For the UK, the benchmark location would be where the Greenwich meridian crosses the Tropic of Cancer. This simple mechanism makes even more daylight available when people are awake than conventional DST, and eliminates political argument.

If you are setting civil time according to when the sun rises, then it is by definition coupled to the rotation of the Earth, and there can be no accelerating difference between them. This is true even if the underlying time scale does diverge in this way because it uses fixed-length SI seconds. This mechanism even lasts beyond the time when the current leap second rules become unworkable because we need more than 12 each year.

He also floated a solution for the pesky Scandinavians:

I thought it would be most convenient to use sunrise at a standard latitude, so that timezone offsets are reasonably simple. East-west offsets are multiples of an hour. Northern and southern zones have fine grained daily adjustments in counterphase to each other, and tropical zones follow mean solar time. The tropic of cancer seems like a reasonable choice of standard latitude for countries in the northern hemisphere – it results in the offset relative to mean solar time varying up to an hour and a half.

People in polar areas will probably continue to follow the time used in the non-polar time zone that’s most relevant to them, i.e. where their supply ships come from or where the nearest city is. I understand that’s what they do at present.

This was back in January 2009; we haven’t done anything with it since but I am minded to, not least because I’ve always wanted to do a small film on timezone history and including a lot of the content of the book Saving The Daylight which I found to be an epic read… and the climax of the film would be to find some pro-DDST campaigners, drop the concept of BET onto them and see/film what happens.

Maybe I should do a kickstarter?


From Wikipedia, anywhere that’s not grey is on the wrong timezone from a solar perspective:

Note the preponderance of red, ie: countries trying to force folk to get up early.

15 Replies to “Introducing “British Economic Time” aka “Sunrise Time” – the ultimate #astronomy geek timezone /ht @fanf”

    1. Oh God, him too! It’s a disease I tell you.

      I kept the second the length it is, no point in messing around with SI units I reckoned.

    2. ps: I think I can claim dibs having been ranting about this since the early 2000s and met Tony in 2009. Maybe Jonesy riffed on it?

      1. I think it was done as a rant against the usual uptick in timezone silliness back when the clocks went forwards…

          1. I’ve thought using UTC as the standard and then merely changing the societal conventions to work around that to be the way to go eventually. After all, once we, as a species, start to move off this rock timezones become meaningless. The team manning the Mars rovers work on a matian day already.

            To paraphrase, time is an illusion, lunchtime doubly so, especially if you’re in New Zealand.

  1. On “double daylight savings time”: hear, hear. If our friends “over the pond” can handle living in a country which spans 4 timezones, the EU (for as long as it survives) can handle 2, surely.

    However, my view on what we should do – rather than what we shouldn’t – is a little different, but easily summarised: “put the entire planet on UTC, and have done with it”.

    The upsides of this are obvious: no more confusion about clocks “moving” in either direction (thus making audit logs easier to read), no mass software patching whenever some nation decides to change when to start or end Daylight Savings, no “twilight zone” (pun intended) for 2 weeks twice a year, when confusion on international conference calls reigns owing to different contries moving to and from Daylight Savings on different dates – you get the idea. Going back to audit logs again, time will move monotonically forward, no matter how the device reporting it is moving.

    There will also not need to be special exceptions made for the ISS, the Samoans can trade conveniently with whomever they like, without having to manipulate the International Date Line, and if you’re stood at either pole, what your watch says will have meaning.

    The downsides are a bit more circumspect; Wall Street will open at 04:30, our friends in New Zealand will take lunch at midnight, and the world will celebrate New Year at the same instant, instead of us being able to watch the current televisual marathon as celebrations ripple round the world. In the event of a new impending chronological issue, in similar vein to what the Y2K problem was anticipated to be (the end of the Unix epoch in 2038, perhaps?), affected systems worldwide will wrap, crash or “whatever” at the same instant.

    It’s a judgement call, certainly, but I think it has sufficient merit.

  2. In Australia, The states of Queensland, New South Wales, Victoria, and Tasmania are on UTC+10 hours, South Australia and the Northern Territory are on UTC+ 9 hours 30 minutes, and Western Australia is on UTC + 8 hours. (There is a large area of South-Eastern Western Australia that uses UTC + 8 hours 45 minutes, but this is entirely unofficial and the area has a population of approximately 200 people).

    It gets more complicated in summer, when NSW, Victoria, Tasmania and SA put their clocks forward an hour, and the rest of the country doesn’t. At that point, the country manages time zones of UTC + 8 hours (WA), UTC + 9 hours 30 mints (NT), UTC + 10 hours (QLD), UTC + 10 hours 30 mins (SA), and UTC + 11 hours (NSW, Victoria, Tasmania). That unofficial zone in WA remains at 8 hours 45 minutes.

    The border between South Australia and Queensland in summer must be one of the few places in the world where you cross a border going due east and you turn your clock back.

  3. Hmmmm, I’m a supporter of change because I think our days are unbalanced and we end up with not nearly enough light at the end of the day in winter-time.

    Changing the *clocks* may seem like a blunt instrument to rebalance the time everyone does things, but it is, in fact, much easier to do and we already have a mechanism for doing it.

    I don’t advocate CET, because I don’t really care what time other European countries use – as you say we can easily convert. Saying I want to switch to CET makes it sound like I want us to follow what they do, and I don’t. I have no idea what CET may do in the future, but it might not be what I want. So I think that is a red herring – for me anyway.

    mathew wrote a very good essay on the problems of using computers to compensate for multiple times. It isn’t quite as easy as you suggest – as I am sure you realise. Even so, a local time rule might be interesting, although again I’d want to set it so that something other than morning (which you seem rather obsessed with – we clearly had different childhood experiences of school) was the fixed point. Sunset perhaps?

  4. Robert Louis Stevenson wrote:

    Bed in Summer

    In winter I get up at night
    And dress by yellow candle-light.
    In summer, quite the other way,
    I have to go to bed by day.

    I have to go to bed and see
    The birds still hopping on the tree,
    Or hear the grown-up people’s feet
    Still going past me in the street.

    And does it not seem hard to you,
    When all the sky is clear and blue,
    And I should like so much to play,
    To have to go to bed by day?

    I spent many Summers (and Winters) in the Highlands and this always struck a chord with me.

  5. If you are in the sort of job where you are on the phone to people in continental Europe all day long and are in contact with European financial markets, then it is a mild inconvenience to be on different time to them. Plenty of people do this – I have done it myself. People cope, though. London’s financial industry starts an hour earlier than does Paris, at least according to clocks.

    Of course, if you are on the phone to people on the US East Coast all day long, then it is mildly inconvenient to be on different time to them, too, but we are not going to switch our clocks five hours the other way.

    (Of course, the real bitch is having clients to whom you are basically on call in both places, meaning that your workday runs from approximately 8am to 10pm London time. It’s the length of it that is the problem, and moving our clocks won’t help that.

  6. Francis:

    I take your point that we might want to diverge from CET in future so could use something that was called “British Standard Time” but functionally identical to CET.

    However my sense is that doing so would be lampooned in Europe just as the French are lampooned for saying that the world’s longitude system is measured using a zero-point which is 2.33 degrees west of the Paris meridian – ie: Greenwich. Or that Texas has an option to leave the USA. It would be seen as limp jingoism.

    Further it would be like the Euro; once adopted, hard to leave.

    As for being obsessed with morning? As I see it you have three points that could be anchored – sunrise, solar zenith and sunset. The anchoring of zenith to noon is precisely what people are arguing about, to anchor sunset to (eg:) 8pm means that in high summer folk rising at 8am would have missed 3+ hours of usable sunlight – the exact arguments which brought about the early arguments in favour of daylight savings – and would be deeply affected by latitude.

    So, to my mind, one must anchor sunrise to a clock’s time for nominal human wakeup. 8am sounds good, and the pre-sunrise glow for an hour or so provides enough light for the early risers; and with winter it will still be a tad darker before sunrise.

  7. One advantage to Francis’ suggestion of anchoring sunset to a time would be that you could take your lover out to dinner and guarantee a romantic level of darkness shortly afterwards.

    Might be a bit of a population explosion from that.

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