I don't think this will directly lead to that happening. Assuming 1.8µs/day, then it will take about 1/(365.25*1.8e-6) ≈ 1500 years for a 1 second difference to

I don't think this will directly lead to that happening. Assuming 1.8µs/day, then it will take about 1/(365.25*1.8e-6) ≈ 1500 years for a 1 second difference to accumulate. I believe the effects of terrestrial bodies have a much larger effect.