If you’re a regular reader, you might know that I occasionally play with different ways of representing time. I’ve come up with my latest version which I call UIT, and you can see it on github.
Why do we need a new clock? Well, you could ask William Burke. On the 31st of October 1828, William Burke and his co-conspirators murdered Mary Docherty, the last in a line of 16 murders they’d committed in order to sell the bodies to the medical profession. When the law finally caught up with them, Burke and his partner, Helen McDougal had already disposed of the body and agreed their story; Burke did indeed meet Mary Docherty in a pub and invited her back to stay with them, but she’d left before 7 and they had no idea where she’d gone. When the police questioned them separately, Burke insisted that she’d left at 7 in the morning while Helen swore she’d left at 7 in the evening.
It can be difficult to get your story straight when you’re dealing with time, but Burke and McDougal got off lightly. In September 1999, three terrorists died at the same time in two different cities. Both groups were killed by the bombs they were transporting which were set to go off at 17:30. The confusion was simply that the bombs were set to go off according to Palestinian Daylight Savings Time while the guys driving the cars had made their plans on Israel Standard Time.
Even if you’ve never found yourself hanged or blown up over a clock confusion if you’re anything like me you’ve still made plenty of mistakes with clock arithmetic and daylight savings time.
So why is the clock the way it is? Dividing a ‘day’ into 12 parts was something that the ancient Egyptians started. They liked to set their sundials up with a dawn and a dusk hour, and ten full daylight hours. Since it was based on the hours of sunlight, the length of an hour would change with the seasons. In 1500 BC, the Egyptians had already invented a portable shadow clock, the spiritual precursor to the modern watch.
The Egyptians were not alone in preferring to divide things into twelves. The Babylonians had a similar obsession inherited from the Sumerians. The Sumerians were one of a group of peoples who independently invented writing around 3500 BC. The Sumerians pretty much invented civilisation as we know it, but they had inherited the Wheel and a number of other important advances from a culture that was lost to climate change (the 5.9 kiloyear event), the Ubaid culture. Anyway, for the Sumerians, counting to 60 seems to have been as natural as counting to 10 is for us. One suggestion for how they may have done it is by using five fingers from one hand to point to one of the 12 finger joints on the other hand, which perhaps explains why they divided the whole day into 12 parts (each around 2 of our modern hours).
When you’re wondering when to get up, when to eat lunch and when to feed the animals, measuring time according to the amount of light left in the day is a good idea, but when you’re trying to formalise systems and work with people in different parts of the world it becomes awkward. The ancient Greeks decided that the Egyptian system of variable length daytime hours was no good, and started splitting the day into 24 equal length hours. This was quite a big change and was by no means universally accepted until the advent of mechanical clocks made it by far the easiest way to measure time.
But why have we kept such an ancient system? After all, the Babylonians tended to measure things based on the lengths of various body parts or the weight of a grain of Barley. We don’t do that any more, but we seem to have carried their predilection for 60s into an age where it’s pretty inconvenient.
A New System
When you’re trying to come up with a new system, nature throws a couple of roadblocks in the way. There are two extremely useful natural time periods – the solar day, which is a nicely predictable cycle of light and dark, and the solar year which is a larger cycle of weather and temperature. Unfortunately in absolute terms, both vary annoyingly making them unsuitable for use in science and engineering, and even worse, the solar year is not an integer multiple of the day.
I think that while science and engineering may need a fixed length period of time, perhaps based on a fraction of the speed of light, this is not particularly useful for day-to-day use. So I wanted to choose a humane system based on either the length of a year or the length of a day. Ultimately I choose day, because I find it more useful to have lunch at the same time every day than to buy a winter coat at the same time every year.
The obvious choice therefore is to measure everything in fractions of a solar day. Astronomers typically do this with Julian Day measurements. I’d already hit on this by accident – if you create time units based on tens and hundreds, what you are actually doing is just naming some of the different places in the fraction of a day decimal. The places that relate most closely to what we currently do are to have hour-equivalents which are tenths of a day, minute-equivalents which are hundredths of an hour-equivalent, and second-equivalents which are hundredths of a minute-equivalent. Interestingly, the second equivalents come out fairly close to old-style seconds, and calculations become incredibly easy – 8:30 plus 5:80 becomes 1 day 4:10 (or 0.83 + 0.58 = 1.41).
But solving my difficulties with Dr. Kawashima’s Brain Training was not the extent of my ambition. I’ve also had to work extensively with people in distant timezones, and it can be very confusing to know when you’re actually going to have a meeting, so I wanted a time that was numerically the same everywhere. We could do this already – everyone could use GMT for example, but that’s awkward, because it’s not obvious what time midnight or noon is where you are. Actually, it’s currently not obvious when noon is, because you probably don’t live at the exact center of your time zone. For example Oxford Time should be 5 minutes and 2 seconds behind Greenwich Time, but with the old system, this is too difficult to represent. These days, we can calculate this kind of thing exactly, so my new clock requires access to your GPS coordinates. While the numbers stay the same for everyone, their position on the clock face always ensures that your local solar noon is at the top of the clock face and solar midnight is at the bottom of the clockface, with high accuracy. Another benefit of having the whole day be one complete rotation of the clock is that I can draw on the dark and light times, based on your location with sunrise and sunset marked on every day.
Of course, choosing the day to have your IM meeting can be difficult too, since days start at different times for different people, so I’ve invented a new set of days, with a base 10 as well, going Nullday, Unday, Duoday, Triday, Quadday, Pentday, Hexday, Heptday, Octday, Nonday. These days form a new 10 day week. Now, I don’t want to replace the 7 day work week (well actually I do, I’d like 4 days on, 3 days off), so I’ve made sure my clock shows the old weekdays too, but when organising meetings, you should use the new weekdays. Instead of months, they get numbered in the year, so the first day of the year is the zeroth Nullday, and the last day of most years is the 36th Pentday, although some years will have a 36th Hexday.
Sadly, I can’t really fix the years, but once everyone has adopted this system of time, perhaps we can work on modifying the Earths orbit to make the years more sensible too.
In order to make the transition easy, I’ve made a canvas based app that should run in your browser (even on mobile devices), which is available here. It can hook in to Google Calendar and draw your meetings on the clock face, it displays sunrise and sunset and shows noon at the top and midnight at the bottom based on your location. It even shows you legacy time too, so that you can still talk to any luddites you might know.
But I can’t be responsible for bad outcomes if you make arrangements to plant bombs or evade justice with anyone still using the old time system.