> 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

> 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.