If you look below the timeline's sequence of frames, you'll see various information about the timeline - the frame number the scroll head is resting on, the frames per second, the number of seconds elapsed for the current frame head position, not to mention buttons for onion-skinning, markers, etc. If you double-click on the number showing the framerate (in this case, 12.0 fps), it'll automatically open the document properties. Ostensibly this is so you can easily change the framerate...but if you need to change the document size, background color, etc. while you're there, who's to stop you?

