At the end of the day there's always skew; crystals in systems aren't made to perfect tolerances. In fact I'm not even sure how you would define perfect tolera

At the end of the day there's always skew; crystals in systems aren't made to perfect tolerances. In fact I'm not even sure how you would define perfect tolerances for clocks in a meaningful way. So at the end of the day it doesn't matter if it's in 'error' or a fundamental to the physics even under perfect conditions. Neither are really under your control and both have the same answer. > You can't escape answering the question: do I care about the time elapsed at home or the time elapsed here? We already have that concept, in the difference between CLOCK_WALL and CLOCK_MONOTONIC. You use monotonic for "local temporal reference frame" and wall for "proxy of globally visible temporal reference frame". Wall shifts around anyway as NTP or what have you figures out how skewed off of "actual" time you are.