Mouse control duration of subtitle

In my work I need to add subtitles to my videos a lot. Can I suggest to add a feature that the duration of the subtitles can be adjusted by dragging the vertical line between two sentences in the subtitle? It would speed up production by a whole lot because I can match the length of the sentence with the waveform in the audio track. Inputting numbers need a lot of guessing and trial-and-error so it's very time consuming.