subsync is a simple CLI tool written in Go, that synchronizes SubRip (srt) subtitles automatically. You only have to know when the first and the last subtitle must be shown.

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.