How does Unreal determine the length of a curve?

Hello,
I was following this tutorial and I was wondering how the engine knew at what time it has to loop back to the beginning. For my game, I have a curve that is non-looping and I was wondering if it was going to tick to infinity… Just like the tutorial, I am creating a timeline from C++ and not specifying any length for it.

Thanks!

After looking at the engine source, I saw that it uses the last keyframe as the end point and therefore will automatically stop at that point.