GPS satellites use atomic clocks which <i>don&#x27;t drift</i> aka don&#x27;t become 0.1% slower or faster than they should be. OK, technically they drift, but not enough to be noticeable by anyone. They&#x27;re the standard to which other clocks are compared.<p>According to <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Atomic_clock#Evaluated_accuracy" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Atomic_clock#Evaluated_accurac...</a> existing atomic clocks can drift by 1 second in 100 million or 150 million years. You won&#x27;t notice that in your high-speed datacenter applications over the course of a few decades.<p>(unless perhaps if one is plain broken, and it&#x27;s noticed by comparing to the others and taken out of service)