# Metric time **URL:** \ **Category:** Great Debates\ **Created:** [April 20, 2009, 2:01am UTC](https://boards.straightdope.com/t/metric-time/493686 "2009-04-20T02:01:57Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![ginman999](https://avatars.discourse-cdn.com/v4/letter/g/e495f1/32.png) [@ginman999](https://boards.straightdope.com/u/ginman999)\ **Post date:** [April 20, 2009, 2:01am UTC](https://boards.straightdope.com/t/metric-time/493686/1 "2009-04-20T02:01:57Z")
Metric time, Was it ever considered? Would it be possible? I guess that the earth’s rotation around the sun takes 365 cycles of days and nights makes it pretty hard to make it work. ---
**Author:** ![Captain\_Amazing](https://avatars.discourse-cdn.com/v4/letter/c/6de8d8/32.png) [@Captain\_Amazing](https://boards.straightdope.com/u/Captain_Amazing)\ **Post date:** [April 20, 2009, 2:12am UTC](https://boards.straightdope.com/t/metric-time/493686/2 "2009-04-20T02:12:09Z")
Well, after the French revolution, the Republic established decimal time, with 100 seconds in a minute, 100 minutes in an hour, 10 hours in a day, and 10 days in a week. ---
**Author:** ![The\_Tao\_s\_Revenge](https://avatars.discourse-cdn.com/v4/letter/t/73ab20/32.png) [@The\_Tao\_s\_Revenge](https://boards.straightdope.com/u/The_Tao_s_Revenge)\ **Post date:** [April 20, 2009, 4:33am UTC](https://boards.straightdope.com/t/metric-time/493686/3 "2009-04-20T04:33:54Z")
How long was a french second compared to a normal one? ---
**Author:** ![Gorsnak](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gorsnak/32/7587_2.png) [@Gorsnak](https://boards.straightdope.com/u/Gorsnak)\ **Post date:** [April 20, 2009, 5:08am UTC](https://boards.straightdope.com/t/metric-time/493686/4 "2009-04-20T05:08:09Z")
A bit shorter. There are 86,400 seconds in a day, and there would have been 100,000 decimal seconds in a day, so .86 regular seconds in a decimal second. The decimal minutes would have been longer - 86.4 regular seconds instead of 60. Nothing wrong with that per se, except that our current timekeeping is very ingrained. Plus it doesn’t work for periods longer than a day, since solar years aren’t anywhere near a nice decimal multiple, nor are lunar months. There’s really very little to be gained with decimal time, unlike most other measures. ---
**Author:** ![matt\_mcl](https://avatars.discourse-cdn.com/v4/letter/m/7ab992/32.png) [@matt\_mcl](https://boards.straightdope.com/u/matt_mcl)\ **Post date:** [April 20, 2009, 5:16am UTC](https://boards.straightdope.com/t/metric-time/493686/5 "2009-04-20T05:16:36Z")
Not to be overly picky, but there is a metric unit of time: the second, defined as 9 192 631 770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium 133 atom. It’s one of the small number of SI base units (units not derived from other units). Also, the minute, hour, and day are accepted within SI as “[Non-SI units accepted for use with the International System of Units](http://www.bipm.org/en/si/si_brochure/chapter4/table6.html)”, like the hectare, litre, and tonne (metric ton). Seconds can be used like other SI units, with prefixes. You are of course familiar with the millisecond and microsecond, but all the other prefixes can be used as well, even if they’re usually not. ---
**Author:** ![Napier](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Napier](https://boards.straightdope.com/u/Napier)\ **Post date:** [April 21, 2009, 4:10pm UTC](https://boards.straightdope.com/t/metric-time/493686/6 "2009-04-21T16:10:15Z")
> [@Gorsnak](#): > > […] There’s really very little to be gained with decimal time, unlike most other measures. I disagree. A solar year, and the passing of the seasons, don’t work very neatly with large multiples of seconds, that’s true. But there are all sorts of calculations one does with time that are more convenient all the same. Anything that was on a shorter timescale than the calendar would obviously be more convenient, and anything on a longer timescale than a day or so that did not involve days per se (for example how long a battery lasts) might be more convenient too. We can’t even get the United States to join the rest of the world on other units, so metric time seems like a far flung dream, but I still like the idea. ---
**Author:** ![MEBuckner](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mebuckner/32/2896_2.png) [@MEBuckner](https://boards.straightdope.com/u/MEBuckner)\ **Post date:** [April 21, 2009, 7:40pm UTC](https://boards.straightdope.com/t/metric-time/493686/7 "2009-04-21T19:40:37Z")
> [@Napier](#): > > I disagree. A solar year, and the passing of the seasons, don’t work very neatly with large multiples of seconds, that’s true. But there are all sorts of calculations one does with time that are more convenient all the same. Anything that was on a shorter timescale than the calendar would obviously be more convenient, and anything on a longer timescale than a day or so that did not involve days per se (for example how long a battery lasts) might be more convenient too. > > We can’t even get the United States to join the rest of the world on other units, so metric time seems like a far flung dream, but I still like the idea. As **matt\_mcl** points out, though, the second has not only been incorporated into SI, it’s one of the base units used to define all other units. Changing it from what it is now to 0.864 of that value would raise holy hell with the entire metric system of measurement. It ain’t just us backwards Americans who would scream bloody murder over that one. ---
**Author:** ![bengangmo](https://avatars.discourse-cdn.com/v4/letter/b/50afbb/32.png) [@bengangmo](https://boards.straightdope.com/u/bengangmo)\ **Post date:** [April 23, 2009, 3:00am UTC](https://boards.straightdope.com/t/metric-time/493686/8 "2009-04-23T03:00:08Z")
Well if nothing else metric time (excepting changeover confusion) would erase a lot of confusion…hmmm 8.5 hours - do they mean 8 1/2 hours or 8 hours 50 minutes? Then with a 10 hour day, “military time” would not be needed, I’ll see you at 5 oclock would be really clear. On the other hand, things like school may be harder to manage, as well as appts etc. At the moment a one hour, 1/2 hour or 1/4 hour time slot is easily managed. If one hour is 144 (current) minutes, not so easy to split up and manage… ---
**Author:** ![AHunter3](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ahunter3/32/368_2.png) [@AHunter3](https://boards.straightdope.com/u/AHunter3)\ **Post date:** [April 23, 2009, 4:15am UTC](https://boards.straightdope.com/t/metric-time/493686/9 "2009-04-23T04:15:51Z")
Within the early history of the SDMB, I annoyed folks several times over with my proposal that we switch to millidays. Within those threads it was pointed out to me, as upthread here, that the French had played with the idea, and that scientists use attoseconds thru petaseconds and to heck with other units of time. I still like millidays the best.