Time is a concept by man but it is used to describe the change of state of a system. So taking a subset of the universe that is a box, if the box is at 0 K and all particles that have mass within the box is completely frozen, then time is not passing in its frame of reference. Of course assuming there is constant change outside of that system, something outside can disturb the box and set it in motion again. So if the universe was frozen, then time would effectively be frozen. But if the universe is the only set in existence then that means if it were frozen, it would never be unfrozen without outside interference. Obviously the universe is not frozen, so all measurements of time is with respect to the constant change of the universe.
When you travel closer to the speed of light it requires more energy to increase your velocity the same amount when you were stationary. So given that the limited amount of energy you started with, as you move closer to the speed of light you have less energy in your body to set your atoms in motion at the same speed relative to stationary. The particles in your frame of reference are slowed down. However from your humanly perception you will not notice a change because your brain is moving at a relatively slow speed too. So given the example of a clock, the clock now only has the enough energy to move at an extremely slow rate. But with all particles of mass slowed down, then for all intents and purposes time has slowed down. Remember we defined time as the change in state. If there is no change, no time has passed.
So in effect time is dilated in that for all intents and purposes there is a proportional difference in the actions of a clock at .99c with respect to a clock at rest.
If there are any experienced physicists who would like to correct anything I said, please, do so because I pulled that out of my butt with limited knowledge of relativity.