Time is always one second per second, it doesn't change, and you had better hope it doesn't if you want science to work since all science is based on ratio and interval. Also, a clock doesn't actually measure time itself, nothing really can. Clocks measure some kind of consistent cycle or change like the swing of a pendelum, number of ocillations of a quartz crystal, phases of the moon, number of sun rises, etc. You can improve the accuracy of your clock but only in relation to some other clock, not time itself. Strange that the article talks about space time since nothing actually moves in space time, it's a mathematical space not an actual space, and is not capable of modeling the behavior of such complex movements such as an object at rest that begins to accelerate.