how to change timing of captions at start /end of video? SO I don’t have 1st and last captions covering my intro / outro

The timing of caption 1 starts at 0:00, but I don’t want it to start for 5 secs or so to allow my intro stinger not to be covered. It won’t seem to let me edit the timing of the caption start time?
Same at the end of my video, the last caption goes right until the end of the video covering my outro stinger? how can I adjust this?
 
Thanks,
Michael