Not aware of an automatic method, but maybe you could add the duration to the clip name?
yes, you would be able to tell this.
The MovieClip has the properties "totalFrames" and "currentFrame".
mc.totalFrames == mc.currentFrame
then the movieclip is at the last frame.
the properties are "_totalFrames" and "_currentFrame"
properties of MovieClip class
hope this helps
p.s. if this post was helpful, please mark the thread as answered
If u have a movieClip give its instance name as mc
here 24 is my frameRate you can also get it dynamically by trace(stage.frameRate);