Something interesting that Kent Hovind brought up; I'm not sure if this is accurate still, but this is what he said:
Before the atomic clock, the speed of light was observed to slow down at a steady rate, and thus time itself was slowing. With the invention of the atomic clock, time is now based on the vibration of a Cesium 133 atom, and thus as the atom's vibration slows along with the speed of light, there is no way to measure it, since we're gauging time by time.
Sorry if that's too convoluted...I was trying to make it coherent.