The Emergence of Time

The word emergence has its own meaning in biology and biological circles. So emergent property, maybe consciousness is emergent. They're worried about AI. You keep programming up AI. But I've been, if you get enough data points coming together with enough computing power, then all of a sudden it's not that you made it intelligent enough to become sentient. It just becomes that because of those things. If time speeds as we leave Earth's gravity and slows with velocity, how will astronauts traveling to Mars be affected? Does it no longer slow? Do they only be impacted by the speeding up of time because of their velocity? How long will a three year Earth journey be for them?