Conversation so far:
who wrote the script for the film Rosmary's baby?
The film Rosemary's Baby was written by Roman Polanski, based on the novel Rosemary's Baby by Ira Levin.
What was Roman's Polanski's inspiration for the story?
The film Rosemary's Baby was written by Roman Polanski, based on the novel Rosemary's Baby by Ira Levin.
Who wrote the novel Rosemary's baby?
The film Rosemary's Baby was written by Roman Polanski, based on the novel Rosemary's Baby by Ira Levin.
Did the author Ira Levin have any input into the script for the film Rosemary's baby?
The script for the film Rosemary's Baby was modeled very closely on the original novel and incorporated large sections of the novel's dialogue and details.

Question: How long did it take to write the script?
Self-contained rewrite: How long did it take to write the script for the film Rosemary's baby?