Does the Buddha speak of the nature of time, vis-à-vis "past," "future," and "present?" Physics shows that what we percieve to be the unidirectional arrow of time is an illusion; that time doesn't necessary "flow" in any direction, and that the concepts of past and present are ultimately meaningless. Is there any discussion of the nature of time as a concept in  Buddhist teachings?
Lord Buddha definitely does talk about Past, Present and Future; but I guess your questions is mainly about, "Do we have something called time?" or "What is time?"

With regards to Abidhamma, there is no "Paramartha" dhamma which we can relate to time: i.e. there is Citta, Cetasika and Rupa and Nirvana, but no reference to time. One of the best explanations I've heard is that the impermanence (Anicca) that we see is what we comprehend as time: i.e. the change that we see, is what we associate with time.

Sorry if it's not very helpful.