Working with Sequences > Editing Sequence Steps > To Set Start and End Times for Step Animation Keys
  
To Set Start and End Times for Step Animation Keys
1. In the Step Editor tab, select a step that contains camera or content animation.
2. In the Keyframe Editor , select one or more rows of animation keys to set their start and end times.
3. To set the Start and End time, type or select a percentage of the step duration to increase or decrease the animation time, or accept the default.
4. Click OK.