Some people say that they wrote their script in two weeks, but this is a bit of a lie. They may have actually sat down and written it in two weeks, but they had been thinking about it, or even making notes or outlining, for many weeks before. Either that, or their script sucks. (Of course by “sucks” I mean that it is bad, not that it did or didn’t make millions of dollars.)
I was listening to the writers of Up talk about the writing of their script. There were a few of them, and Pixar has a unique way of working, but it took them a year to get to the first draft. They took their time. And for them, the writing goes on through production in a way only computer animators can fathom. It took years from their idea.
TV writers are used to working very fast. They generally get a couple weeks to put a script together, so when they move into the movie world, they brag about how fast they can work. But TV is a lot of dialog, a lot of retrenched themes, it’s not as plotted and what plots there are tend to be fairly formulaic, the shows all have their “world” already created so that doesn’t have to be created every time. A film script needs more than that. A film script needs ideas.
I’ve heard many writers talk about how long a script takes to write and it seems the general consensus is between eight months and a year. For a first draft. Once you have that first draft, then you can work quickly on rewrites, depending on the situation. It doesn’t seem to matter if they outline or not, or even if there’s a writing team (although the teams tend to be faster).
The reason it takes a long time to write a film script is that a good script needs a lot of ideas and it takes time to come up with them. The ideas also have to fit into the story. And they all have to be good ideas. A million bad ideas get thrown out along the way, and that takes time.
Imagination takes time.