Scale Keys - Time moves all selected keys proportionally toward or away from the current frame. Use Scale Keys in Curve Editor and Dope Sheet to change the locations and time spans of all selected keys.
The scale center is defined by the current time set by the time slider. You can scale keys about any moment in time by positioning the time slider before you use Scale Keys.
Select an animated object, then right-click and choose Curve Editor.
The following steps work in both Curve Editor and Dope Sheet modes.
(Scale Keys) or from the Keys menu choose Scale Keys - Time.
Drag away from or toward the current time line for the following results:
The scale percentage is displayed in the Show Selected Key Stats field as you drag the selection.