This is a very old problem and not limited to spacecraft. If you sail around the world eastward, each of your days is slightly shorter than the days of your cou

This is a very old problem and not limited to spacecraft. If you sail around the world eastward, each of your days is slightly shorter than the days of your countrymen and by the time you get home, you will have experienced a full additional day-night cycle. I think the solutions would be the same: separate timekeeping standards where it makes sense, like Mars, and frequent corrections to spaceships' clocks to keep in step with a universal standard like UTC as sailing ships used to do[1]. 1. https://en.wikipedia.org/wiki/Noon_Gun#Time_signalling https://en.wikipedia.org/wiki/Noon_Gun#Time_signalling