Small improvement to the timeline.

The problem isn't the timeline. It's that the orbit was stuck on three seconds but the timeline was giving you five. The length of the timeline is the duration of the longest spin or orbit in the scene, but I've seen it occur that an orbit executes in three seconds no matter the duration is set to. This might happen if you accidentally assign an orbit animation to an object that is not a camera and forget to clear it. I haven't nailed this down, but for sure what you saw was the timeline responding to the duration you entered while the actual orbit was stuck on 3 seconds.

I ran a test just now with two objects spinning and a camera orbiting, and there are no "non-animating" orbit frames at the end of the series.

Thanks.That make sense.

Mainly when rendering in image sequence. There have been times when I've wanted to do a 5-second orbiting camera rotation animation. Knowing that 10 seconds at 30 frames per second gives a total of 300 frames, I set the render time to half that (250 frames in total). Well, when I checked all my export images, I noticed that the last 56 frames were strictly identical. No anim. That's why it would be nice if the timeline readjusted itself according to the set duration.

Thanks for idea. Can you clarify why it would be useful?