I spent most of today revising my mess of a screenplay. As usual, whenever I get stuck, I go back and revise. Usually once I've sorted out whatever problems there are, my writer's block melts away. Usually. Not always. (Some writers label their drafts: Draft 1, Draft 2, etc. By the time I've finished something, I'm usually on Draft 394* or something like that.)
It's obvious by this point that I won't finish my screenplay in twenty-one days, whatever the book says. But I'll take it as far as I can before time's up.
*Yes, this is an obscure Harry Potter reference.