annleckie:

Ancillary Mercy Spoilers. But.

I have given some thought to the timing of 2S Independence Day. And I think it just makes logical sense to say that (given it is nearly impossible to actually line up the Athoeki year with the Terran one) for practical purposes, Independence Day should be celebrated on the Monday after the Sunday after the first full moon after the vernal equinox.

I know that sounds complicated, but the upshot is, 2SID candy eggs and peeps are all half price for the holiday.