original: On September 17, 2004, Whedon announced on the movie's official website that shooting had been completed.
simplifications: On September 17, 2004, Whedon wrote on the movie's website that shooting is finished. Whedon announced on September 17, 2004 shooting had been completed. On September 17, 2004, Whedon announced that shooting was complete. This was stated on the movie's official website. On September 17, 2004, Whedon said on the movie's official website that shooting had ended. Whedon announced on  September 17, 2004,  that shooting of the movie had been completed. On September 17, 2004, Whedon announced that shooting was done. Whedon posted on the movie's website that filming was done on 9/17/2004. Whedon announced on the movie's official website that shooting was completed on September 17, 2004. On September 17, 2004, Whedon confirmed on the official website of the film that the shooting was already completed. Whedon announced on the movie's official website that shooting had been completed.