If I understand correctly,the second law of thermodynamics states that for all processes entrophy is constant or increases,this implies that it can be variable,and as time is 'the distance from one event and another',time is involved in the process.
I totally agree with you Mark on your ideas of concept and physicality,to that end have written a little poem,feel you will understand.
Past and future now are one,
The present with the now has gone.
But who am I ,or am I yet.
Part past yet in the future set.
Then out of time a souless sound,
Like some lost laugh it's mouth had found.
The point I am trying to make is that concepts can frequently see the truth,where equations only produce the proof of'understanding'.....
Not that I am knocking math,but am mindful of the saying,'there are more things my twixed heaven and earth my dear Horatio,than this world dreams of'
Peter