Timeline End Value

I have read a number of questions asking about adding a project and/or slide time to their storyline project. While I understand this is not currently available, I was wondering if it could be created with variables. I have noticed in another development program that the displayed slide time is based on the length of the timeline in each slide. Is there a way to grab the Timeline End value and place it in a variable? Then you could display the slide length for each slide.

Thanks,

Darin