Editing the Timing of Closed Captions
When you edit closed captions, you might need to change the timing, as described in the following procedures. Make sure you select Closed Captions from the Media Pane menu to display closed captions in the Media pane.
To change an In point or an Out point, do one of the following:

Move the position indicator to the timecode where you want to set the new In point, select the closed-caption segment in the Closed Captioning pane, right-click, and select Set In.

Move the position indicator to the timecode where you want to set the new Out point, select the closed-caption segment in the Closed Captioning pane, right-click, and select Set Out.
These commands are also available from the Closed Captioning Pane menu.
To close a gap between closed-caption segments, do one of the following:

To close a gap by extending the end of a closed-caption segment, right-click on the segment and select Close Gap: Modify Out.
The Out point is changed to one frame before the following segment’s In point.

To close a gap by extending the beginning of a segment, right-click on the segment and select Close Gap: Modify In.
The In point is changed to one frame after the previous segment’s Out point.
These commands are also available from the Closed Captioning Pane menu. If the commands are not displayed (context menu) or are disabled (Pane menu), there is no gap between segments.
To change the start timecode of the first closed-caption segment:
1. Click the Closed Captioning Pane menu button and select Modify Start Timecode.
The Modify Start Timecode dialog box is displayed.
2. Enter the desired format for the start timecode by typing the first digit and continue typing until you have typed 8 digits.
For example, a sequence might start with 01:00:00:00, but the first closed caption starts with 00:00:00:00. In this case, type 01:00:00:00. The change affects all subsequent closed-caption segments.
3. Click OK.