I just posted three sections. Two are harmless planet ones, but the third is the basic section on human units in the RP. Unless otherwise stated it will be essentially the same as the modern SI units that the metric system is based on. (Imperial units have no value even now. If you *really* insist their units are all defined relative to SI units anyway.)

For the calendar I'm just going to go with a system largely the same as the present UT systems except with no leap seconds, corrected for relativity, etc to create roughly a true "universal" time. Each days has 86,400 SI seconds, then everything else follows the rules of the Gregorian calendar rules according to that day.

It's to lampshade the usage of human units as a reference more than anything.