The Timeline workflow gives you some real power over the temporal playback of your project. You can Scrub the timeline, and also set Work Area properties on Timeline.
Since every animator has a different preference, you can toggle between Seconds, Frames or switch to a standard time view of H:MM:SS:F
Click and drag on the Timeline to scrub the actual Timeline playback of your composition. By clicking and dragging the Handles at the top of the Timeline the Work Area can also be edited.
Work Area Options
Standard Work Area properties are able to be edited in the text fields like Start, End, Duration and CTI.
One of the new abilities in M⁴ is Frame Snap, which creates an otherworldly way to preview/playback and change Timeline properties. Simply set the Snap amount and Enable Frame Snap — now when you scrub the Timeline; playback will jump every X amount. Additionally, the Work Area handles will also snap using the same range.
Frame Snap is an awesome way to preview long scenes, or save CPU processing by skipping frames.