Question about timeline in blueprint

Since i’m just starting to learn UE4, This question is probably very simple. Suppose that there are two blueprints A and B, and there is a time line T in A. How can i know when T starts and finishes in blueprint B and give a instantaneous “Exec” output which likes what “Event BeginPlay” does? If someone can help, i’ll be very grateful.

Make Event Disptachers on A and have B bind to them.

When A starts the Timeline call your Event Dispatcher and B will get the event too.