Timed Modal Epistemic Logic, tMEL, is a newly introduced logical framework for reasoning about the modeled agent’s knowledge. The framework, derived from the study of Justification Logic, is adapted from the traditional Modal Epistemic Logic, MEL, to serve as a logically non-omniscient epistemic logic and dealing with problems where the temporal constraint is an unavoidable factor. In this paper we will give a semantic proof for the formal connection between MEL and tMEL, the Temporalization Theorem, which states that every MEL theorem can be turned into a tMEL theorem if suitable time labels can be found for each knowledge statement involved in the MEL theorem. As a result, the proof also gives us a better understanding of the semantics on the both sides of the theorem.