Copy Timing will copy the timing & ease data of your currently selected F-Curve. When clicked, you’ll see how many keyframes were copied in Blender’s Status Bar.
Applies the copied Timing and/or Ease to the selected F-Curves. For example, if your copied keyframes were on frames 5, 10, and 15, all selected F-Curves will have new keyframes on frames 5, 10, and 15. With ‘Replace’ enabled, the keyframe on Y Euler Rotation is deleted.
The options for this operation will appear in the Redo Panel at the bottom left of the Graph Editor. The options are:
Remove all keyframes on the selected F-Curve before pasting the copied keyframes.
Paste the Ease along with the Timing.
Paste the handle’s angles along with the Ease.