Trim/Shorten/Cut
https://shotstack.io/learn/use-ffmpeg-to-trim-video/

ffmpeg -sseof -600 -i input.mp4 -c copy output5.mp4
ffmpeg -sseof -00:10:00 -i input.mp4 -c copy output6.mp4
Both of the above two commands will make a cut of the last 10 minutes of the input video.

Cut Front/Beginning
ffmpeg -i $fileOutput1 -ss 00:00:00 -to 00:6:08 -c:v copy -c:a copy $fileTrim
use time on left to cut at the end

The above command uses -to to specify an exact time to cut to from the starting position. The cu