>Unfortunately astronomers care If astronomers care, then by definition, navigators care. For instance, observing the overhead transit of a star and being off

>Unfortunately astronomers care If astronomers care, then by definition, navigators care. For instance, observing the overhead transit of a star and being off by a second translates to hundreds or thousands of yards in location, depending on latitude. FYI, ICBMs still use star positions as their primary means of navigation. But every datum and grid in the world is eventually traced back to, or translated via, positions originally defined by astronomic observations. There's a reason that the Prime Meridian is defined by the meridian that "happens" to pass through the observatory at Greenwich. And while I get the point you're making, in the US, it's still legally up to the Navy to administer official time keeping, and they get to decide how all of the little non-uniform or non-predictable deviations and elements get dealt with in the real world. Including the deviations that result in leap seconds. The fact that most people don't have to think about these things is due precisely to how well the military and scientific communities handle it.