I am learning more about the Einstein Filed Equations. I do not know how to evaluate them. Can someone tell me if time can be a periodic function in the equation for spacetime? i may not have that spacetime correctly stated. Can time periodically vary like a SIN function and still work in the math? I am not just throwing math around. Continuous and counting just varying positive and negative? And what would this do if time parameter went from -1 to 0 to 1 and back again? I am trying to crush my thoughts here.