Post-Production is where you pull all the pieces together. Video, audio, graphics, special effects, and the final polish.
News editing traditionally was expected to take about an hour a finished minute... a 90 sec story = 1 hour, 30 min of editing time. With corporate, music and non-news type of editing the hours can explode. A 3 camera shoot of a seminar could be 8 to 10 hours per 2 to 3 hours. I had edited a graphic intensive piece that was 3 minutes 30 sec long and took 4 weeks.
So the hour per finished minute can work as a baseline and the numbers only go up from there.