Absurdity

So what would the scientifically best way to have the closest thing to metric time be? Assuming we don't have to worry about past systems and can easily switch over to a whole new ideal? Like how dvorak is a better system, but will probably never get switched over.

We are stuck with 365 days a year, those are defined terms. Seconds, minutes, hours, weeks, months, seem like they can all change though. Working our way down, 10 months, or 20 months? Maybe 15? Nothing seems to work perfectly with 365, 36.5 days, 24.3 or 18.25. I think either 10 or 20, and either go 36,37,36,37 for the months, or 18,18,18,19,18,18,18,19. Maybe decide based on the rest of the factors.

How many days in a week? Well if we go with 10 months, we can have 6 days a week, with 6 weeks a month, and one 7 day week every now and then. If we have 20 months, we can have 3 weeks of 6, or 2 weeks of 9, which might divide the months nicely in half. You have the first half of the month, and the second. Could be the foremonth, and the hindmonth. "Oh we're going into the hindmonth now". I think I prefer that actually, kind of more like a metric system, dividing things in half instead of in 6's, even if it's 9 days instead of 10, it's the closest we can get without losing our definition of a day, I believe.

Of course the lunar ideals wouldn't work, and it would be based completely off our ideas of a "day" and "year", months would no longer be associated with a lunar month (however loosely). And at this point I'm stopping as well for this thought experiment, as we are going from calendar time to time time, and while everything previously relied on the definitions of a year and day, I think time time would only rely on the definition of a day, which would still be fixed.

Of course the easiest thing to do would be to change the definition of a day, but it seems poetic that it is aligned with the rotation of the Earth. Plus things wouldn't really make sense, night time coming at random times. Though that might be an interesting detail in some fictional universe, I think this might be an interesting calendar system in some fictional universe as well. This was just a 5-minute thought experiment, I'm sure there are better solutions out there.