>> Any metric time system stumbles on the fact that 1) Days do not even divide into years by 10 and there's not even a whole number of days in a year and 2) calendars should sync with the seasons to provide any real use.
Only because a "year" is a measurement of how long it currently takes a specific planet to orbit its star. On larger scales such specifics don't matter. There is no daylight savings time in space.
"In computing, at least internally, metric time gained widespread use for ease of computation. Unix time gives date and time as the number of seconds since January 1, 1970, and Microsoft's FILETIME as multiples of 100ns since January 1, 1601.[7] VAX/VMS uses the number of 100ns since November 17, 1858 and RISC OS the number of centiseconds since January 1, 1900."
> Only because a "year" is a measurement of how long it currently takes a specific planet to orbit its star. On larger scales such specifics don't matter. There is no daylight savings time in space.
DST is kind of meaningless here. It's not an inherent feature of the calendar and it's a dumb hack that wasn't even great when it was implemented, I'm all for getting rid of it.
Sure yes when we become a multiplanet species maybe metric time will make sense for use at a human level calendar. What I was really talking about was a metric calendar system today and for use on Earth. Even off planet mapping day night to the diurnal cycle will make sense and assuming it's a planet with seasons and a breathable atmosphere the calendar will be more useful if it can match the local seasons. If that becomes an issue we'll probably have a calendar for each planet and then a universal date system used as a translation layer between different calendars and by people living in space where seasons don't screw things up.
As for the variability and year that's just as bad for a metric calendar as our current Gregorian. None of that really matters though because today the calendar needs to work for people living on Earth today. If we make it to mulit-planet/solar system we can figure out Stardates then.
> Metric time is a realworld thing
Only at the level where humans don't really interact with it directly. No one (well I'm sure someone out there does but to a reasonable approximations no one) uses epoch time directly in their daily interactions with people. It's communication layer for machines not for people.
I could see dividing the day decimally working pretty well.
Right now a typical work day is 1/3 of the day. This might be a good opportunity to drop it down to 3/10 of the day. Then you have the work day neatly dividing into thirds for a morning break and an afternoon lunch or vice versa.
Most human level scheduling currently works at a 15 minute resolution anyways so hundredths of a day would be the perfect unit for a lot of things I'd think. Instead of meeting someone at 3:45pm, you'd just meet at today.66 or something like that.
In favor of existing metric time proponents, a kilosecond is 16.7 minutes, which as you suggest is a pretty good unit of resolution for most scheduling concerns during a day of human activity.
The fun problems happen because most of the prefixes between kilosecond and megasecond (nearly a fortnight at 11.6 days) and between megasecond and gigasecond (a whopping 31.7 years) are either deprecated or non-standard to begin with. For instance myriaseconds (10^4 or nearly three hours) might be useful, but myria- was dropped from the metric prefix list for good reasons.
Only because a "year" is a measurement of how long it currently takes a specific planet to orbit its star. On larger scales such specifics don't matter. There is no daylight savings time in space.
Metric time is a realworld thing: https://en.wikipedia.org/wiki/Metric_time
"In computing, at least internally, metric time gained widespread use for ease of computation. Unix time gives date and time as the number of seconds since January 1, 1970, and Microsoft's FILETIME as multiples of 100ns since January 1, 1601.[7] VAX/VMS uses the number of 100ns since November 17, 1858 and RISC OS the number of centiseconds since January 1, 1900."