subsync is a simple CLI tool that synchronizes SubRip (srt) subtitles automatically. You only have to know when the first and the last subtitle should be shown.
examples
subsync -f 00:01:33,492 -l 01:39:23,561 -i file.srt
In the above command the input is the file.srt. We set the first
subtitle to be shown at 00:01:33,492 and the last to be shown at
01:39:23,561. The synced file will be saved at file.srt.
subsync -f 00:01:33,492 -l 01:39:23,561 -i file.srt -o newfile.srt
The above command is the same as the previous one, but the synced file
will be saved at newfile.srt.