We recently added a mechanism that allows you to log any information you find helpful during training. Please take a look at this page.
You can use the same mechanism to log time, but with MATLAB environments, unlike Simulink, there is no intrinsic notion of 'time'. You just assume that every time you call step in your environment, 'some' time has passed since the previous call. For some applications it makes sense to consider that these step calls happen at fixed time intervals, for others (e.g. event-driven systems) it may not be the case.
