Time dilation, time slowing down, as well as length contraction, mass becoming smaller and denser, come out of Einstein's equations because he wrote it into his equations by having his equations based on his theory that nothing of mass can travel faster than the speed of light and that the speed of light is the fastest possible speed (an upper speed limit) of the universe. Einstein's equations, which he modified from the equations written for Relativity by Marcel Grossmann, were based on Einstein's theory of how the universe worked. Therefore, simply solving the equations will give you no information about whether or not the results which they give are of any value. Equations give you the results they were written to give, but those results are only of value if the theory on which the equations were based was correct. Consequently, to know if there is time dilation and length contraction one does not solve the equations, as they were written to produce those results, one analyzes the theory from which the equations came; if the theory is wrong then the equations will provide wrong results.
The documents in my main paper: "Einstein's Theory of Relativity Misconceptions & Errors" and in four of my supporting papers, "Black Holes & Gravitational Lensing Misconceptions", "Einstein's Math Question", "Einstein's Doubts and Errors" and "Scinece's Questionable Information About Einstein and Relativity", provide ample proof that Relativity is wrong, that Einstein knew it was wrong, and that scientists around the world pretend that it is a valid theory because it pays them a lot of money to keep researching it. As Relativity is wrong it is logical that time dilation and length contraction and the constancy and of the speed of light, and the speed of light being the unattainable (by objects of mass) speed limit of the universe, are also wrong.