Temporal Logic, a branch of Modal Logic, exists to abstract the impossible, the possible, the necessary.  Such that:

P{x,y}

where y achieves, gains, or has the P referent through Time via x and P is a quality or a quantity - All XOR Some XOR None. If we get lucky, the quantity maybe first order - 'a' number assigned to 'a' variable, tho' it's much more likely to be a second or greater order quantity, such as a Complex Number, or a series of mathematical statements grouped into inter-related families of mathematical statements.    

One result of this, using the Lowenheim-Skolem Theorem, is the (potential and unpredictable) bifurcation of model functions from D -> T to D -> T' where T' is who-the-hell-knows-what.  ;-)  One known occurance of this is the transformation, in Catastrophe Theory, of control to state or state to control variable(s).  Time, then, can become a control variable in certain of these transformations.

Modeling (certain) Feedback Loops, therefore, we have to acknowledge the potential for Time to 'jump' between playing a role as a control or as a state variable leading to qualitative change of of the Fitness Landscape.

Note:  I am not saying Time isn't constant.  That would be ... weird.  

Have epistemological model of Complex Information environments. Will Travel.