Pre- And Postrecord Time

#1
Maybe I am stupid but I cannot find any parameters to set a prerecording and a postrecording time for scheduled records.

Sometimes movies are not exactly on schedule, so I prefer to begin recording 10 minutes before the scheduled begin of a movie and also stop recording 30 minutes after the scheduled end of the movie.

Records scheduled via EPG in ProgDVB oftn are clipped at the beginning and end - so I desperately search for this feature instead of manually correcting the scheduled commands.