How does in game time work?

[zrtelford]

I know timeofday/lighting/weather/ is in the game, but is it truly dynamic? Is it based on Pitch count, so quicker innings make in game clock go slower? I know Matt sometimes mentions games going quicker, and I try and look at the in stadium clock, but I can't say for sure if games move quicker or slower depending on runs scored, pitch count, number of batters or what, curious if anyone else has more accurate conclusions. Btw, I love the feature.

[Detroit Tigers]

Lighting changes batter by batter. Time of game is pitch count.