It's totally a guess.
Does this change affect space as well? In our current best supported explanations, space and time are an inextricable continuum.
Nobody in science is looking for "proof". It's all about explaining a phenomenon, modeling it, and then looking for evidence to support the explanation. Any one thing can show an explanation to be false, but supporting an explanation is an ongoing, never ending process. We always want the best supported explanations, and when we can't find anything wrong with one, we start calling it a theory. Proof is for formal logic and maths.
So, do you have any evidence to support your idea that time has evolved?