I'm sure you can change the scale (timeline) at the top of the arranger to elapsed time from the default bars (measures). I don't have it in front of me at the moment, but I'm sure it's not too difficult to figure out.
Hiya my friend. Right Mouse click the line above track 1 and below the slider bar at the top of the screen. This pops up a drop down menu that gives you 4 options one of which is DISPLAY MILLISECONDS. Left click this option & a tick will appear beside it. This then gives you the lenghth of your arrangement.