Time is observer-dependent, any universal measurement of time is going to be somehow "inobjective" given relativity (and FTL travel). I haven't seen the Human

Time is observer-dependent, any universal measurement of time is going to be somehow "inobjective" given relativity (and FTL travel). I haven't seen the Human Universe but e.g. Voices of a Distant Star, A Fire Upon The Deep, and Interstellar all touch on time dilation as major plot points. Gundam standardised space colonies on the Universal Century (earth time) but that was over much shorter distances.