Back in my pulp-mag days, I worked from about 8:30 to noon, took an hour off for lunch, and worked again from one to three, for a work day of five and a half hours or so. I wrote 20 to 30 pages of copy in that time, doing it all first draft, so that I was able to produce a short story of 5,000-7,500 words in a single day.
– Robert Silverberg