Well space and time are one dimension, a single fabric in relativity. So as space is warped, as predicted by relativity, time is also warped. The more warped, the more time is slowed down. Now as for acceleration. We can see why time is slowed down depending on reference. If you have a person in a train, shining a light, they will measure the speed to be c. But for an observer outside the train (which is moving) they will see the light going c+(whatever the speed of the train is). Now this can’t be right. Light can’t be going faster than light. Light is always c. So the idea is, the person outside will measure c because of this rule. So how? Because time will slow down for his frame of reference to allow for the light to travel at the speed he would supposedly measure. Something like that. Lemme know if you get it. I can elaborate( or maybe I made some mistake)