How to use Subtitle Workshop to create or edit your subtitles
Automatic durations
“Automatic durations” is a very useful feature when you have a subtitle file in which the duration of all (or some) subtitles is totally wrong. By specifying a time per character, word and line (the default values give very good results) Subtitle Workshop will calculate the appropiate duration for the subtitle. Another use this feature may have is when subtitling videos, to go faster you can only set start times manually and Subtitle Workshop will calculate all final times. To access “Automatic durations” click the “Edit/Timings/Automatic durations” menu or the [Shift]+[Ctrl]+[R] keys.
You can additionally specify if you want to apply new duration in all cases, only if it is greater than original or only if it is smaller than original. You can also apply calculated durations to all the subtitles or just the selected ones.
The use of this feature together with Duration limits and Detect too long/short durations from Information and Errors can give excellent results in a short time.
Shift subtitles
This feature moves all the selected subtitles initial time a specified number of milliseconds forward/backwards, without modifying their duration. To shift selected subtitles forward, click the “Edit/Timings/Shift +X milliseconds” menu or the [Shift]+[Ctrl]+[H] keys. To shift selected subtitles backwards, click the “Edit/Timings/Shift -X milliseconds” menu or the [Shift]+[Ctrl]+[N] keys.
Cf. How to split your subtitles file with Subtitle Workshop