Who wants to talk with me about interplanetary calendars?

I just finished the old book that's been on my to-finish for ages about the history of calendar reform, and it was surprisingly interesting for a book that consists in large part of quotations from Hansard and League of Nations committee reports (the one about cross-cultural perceptions of time is still on the to-finish for awhile yet, sorry.) They both ended up on that pile after the first time I read Machineries of Empire and was curious about how the calendar-based magic system in that might actually worked. (Mind you I don't think the MoE system can really be specifically calendar-based in its actual mechanics, also the farther I got in the calendar reform book, the less reasonable Cheris's quick-change reform seemed, and it didn't seem that reasonable even to start with.)

But! Calendars in worldbuilding are an interesting thing to think about, and I don't think I've ever seen a system used in a multi-planetary polity that really made sense. You have systems like stardates (that was a deliberate throwing up of hands at the idea of coming up with a workable one) and ones that just copy Gregorian time-words without really putting much thought into it, and not much else. (It's amazing how rare it is to see a SF story that doesn't have a very-nearly-24-hour day cycle, even. Where is the spacelag of shifting from a 30-hour day to a 20-hour day??)

So. ( Interplanetary calendars. )

Anyway, basically, this is my plea to work that kind of calendrical and timekeeping nonsense into more of your SF. It's fun! I swear!