The Select New Duration dialog allows you to change the duration of a slide in the sequence while in the Sequence Style of Storyboard. Click the ruler button of any slide on the slideshow to open the Select New Duration dialog.

To change the duration in the dialog, enter a new duration in seconds into the field, then click the OK button to save. If a shorter duration has been entered, the time will be taken off the end of the slide. If a longer duration has been entered, any time remaining after the slide's current out point will be added back on, up to the total duration of the slide. A slide cannot be made longer than its original length using this method.

Note that this method of editing slide lengths is best when precise lengths have been predetermined. If you prefer to line your in and out points up to visual cues on the slide, use the slide navigation buttons in the Selected slide Preview area to cue up the precise moment of the in or out point, then use the red and blue flags to mark the in or out point.