One Galleon is 17 Sickles and one Sickle is 29 Knuts... The wizarding currency isn’t too simple or practical, is it? Muggles also have struggled for ages with overcomplicated, inconsistent systems of units. But then we adapted the SI – and since then we got used to using this simple, decimal system.

There is one thing though that we still measure in strange units. 60 seconds go in a minute, 60 minutes go in an hour, 24 hours go in a day. There’s 365 days in a year, except when it’s 366, and they can be divided into 52 weeks of 7 days, with some days left over, or alternatively into 12 months of 28, 29, 30 or 31 days each, depending on... reasons.

Could we simplify all that mess?

Of course we could. I don’t think we will though. Many people have tried and failed. Still, why not think about it, purely theoretically?

### Time

A day is pretty easy to divide into 10-based fractions. If we divide current 24 hours into ten parts, we end up with 2.4 hour = 144 minute blocks. If we divide those in a hundred parts, we get blocks of 86.4 seconds. Both units (1/10 of a day, and 1/1000 of a day) seem to be just as useful units of time, as “hours” and “minutes”. But instead of being a 24×60×60 system, it’s the familiar 10×10×10.

That’s basically how Swatch Internet Time works. Simple and useful, what more could you wish for?

### Timezones & DST

Daylight Saving Time is passé. John Oliver asks “How is it still a thing?”, the European Union prepares to finally abolish it. It’s useless and just causes trouble.

And what about timezones? They’re a huge improvement over local solar time already, but in this globalised world what if we got rid of them altogether? Instead of 14:00 in Berlin being 8:00 in Washington D.C., the same number would mean exactly the same moment in time. That’s already how many computers keep time – as a number of seconds since 1970-01-01 00:00:00 UTC, they just display it differently for different people (see Unix timestamp). What if “@500” meant exactly the same moment, regardless of where you are? It just happens to be in the evening in Amsterdam, but around noon in New York.

### Calendar

Which day of week was November 19, 2013? Well, I know that, because it’s my anniversary, but otherwise, I’d have to look it up. We need calendars (or some extra effort counting days) to simply find out which day of month is it on the Thursday in two weeks. We need to take a moment to figure out how many days does February have this year...

What if there were no difference between “month” and “week”? If dates were predictable, the same each year? If it was all 10-based?

Say hello to the French Republican Calendar, which does exactly that. I’d rather use a slightly modified version, but the main idea stays the same:

The year is split into 36 weeks of 10 days. The remaining 5 or 6 days form a special half-week and the end of year. If we start indexing from 0 (as we already do with time, the clock starts at 0:00, not at 1:01), we can easily see from the date, which week and which day was it – for example day 123 is the day 3 of week 12. Simple.

### Demo

I’ve decided to write a simple script that converts our current date and time into this decimal-based system. As a starting point I’ve chosen the first day of spring, 2000-03-21 06:00 UTC (leap year rules stay the same).

Here’s how it works in practice: