Print farm shift calculation

For example, you can set up that the employee’s shift is from 8:00 to 18:00. Three prints are scheduled to be printed, each of them takes 6 hours. So first print is started at 8:00, finishes at 14:00 and another is started immediately, but it finishes at 20:00. The last print can only be started at next day 8:00, so the total time would be 3*6h+12h (time during which noone can start the print). This could well be shown in the Gantt chart and long term print planning would be many times easier.