Texture Interpolation in Materials?

Is it possible to do a looped Ping Pong Interpolation between two textures in a Material (0 → 1, 1 → 0) ? I can interpolate by attaching a Time Node to an Interpolation node but I have limited control and can’t do a Ping Pong loop. I see no way to get logic out of the time node to flip it (once it reached .99 for example). I will do this in blue print with a dynamic instance if I have to but I’d like to avoid that if possible.

Thanks

Time->Sine->ConstantBiasScale (0.5 scale,0.5 bias) -> Alpha