Am I the only one who’s annoyed metric time was never introduced together with the metre, the gramme and the other metric units?
I think the basic unit should be the day, so that we’d have some nice units such as deciday (slight less than 2.5 hours), centiday (almost 15 minutes) and milliday (almost a minute and a half). Just a shame there’s no SI prefix for 1/100,000, because this fraction of a day is the closest one would get to a second (0.864s, to be precise). I guess people would just say “second” in everyday speech and mean 10µday, just as “minute” would be a sloppy way of saying milliday.
Looking at longer time scales, the decaday could replace the week, the hectoday the month, and the kiloday the year. It would of course have the slight drawback that holidays wouldn’t fall on the same point in each kiloday (because it wouldn’t be aligned with the solar year), but moslems already have a similar problem with their calendar, so I’m sure we’d get used to that quickly. A ten-day week would lead to different working patterns, I guess – seven days at work and a three-day weekend, perhaps?
To honour the people who introduced the metric system in the first place, I think kilodays should be counted from the start of the French revolution, that is, day 0 would be 22nd September 1792. That would make today day 78,524 (kday 78, hectoday 5, decaday 2, day 4).
It would be really practical! Given that I was born on day 516, kday 65, it’s so simple to calculate my age as 78,524 – 65,516 = 13,008 – in other words, I could have celebrated my 13th kiloday birthday eight days ago.
There’s more information about the metric day here, by the way.