In this talk, I will discuss recent results on the boundedness of time derivatives for solutions to parabolic p-Laplace equations. The main idea is to combine the Bernstein technique with a suitable approximation scheme. As a consequence, we obtain an optimal regularity result with a connection to the well-known C^{p'}-conjecture in the elliptic setting. Finally, we extend our method to treat global regularity results for both fully nonlinear and general quasilinear degenerate parabolic problems.