It certainly seems that way, but one of the fundamental rules here is that you can't ordinarily trust clocks to keep in sync, they drift, jump backwards and for

It certainly seems that way, but one of the fundamental rules here is that you can't ordinarily trust clocks to keep in sync, they drift, jump backwards and forwards etc. Google solve this problem using synchronized atomic clocks in their data centres, which is not an option for most systems running on commodity hardware.