The Time Editor is a comprehensive tool for creating and editing animation. It combines animation editing workflows from existing editors to give you an intuitive, clip-based workflow for non-linear animation editing that lets you easily navigate between clip-level views and key-level details.
Any object or attribute in Maya for which you can set keyframes can be brought into the Time Editor as a clip, which can be edited in a non-destructive way. The Time Editor defines the timing operations (for example, speed, length, start/stop times, and so on,) of animation, so you can experiment with combinations and variations of elements in your scene. When you create a version of the animation you like in the Time Editor, you can bake it so that the new animation can be used in Maya.
Watch the video for the workflow.
For full details on the Time Editor, and more information about what you can do with this feature, see
Time Editor in the Maya Help.