Simple PHP scripts to adjust the offset or fps of .srt files.
To add 13.3 seconds to the .srt file:
php SRT_add_remove_offset.php <SRT file> 13.3
To remove 5.3 seconds to the .srt file:
php SRT_add_remove_offset.php <SRT file> -5.3
To change the frame rate of the .srt file to 133%:
php SRT_change_to_rate.php <SRT file> 133