Question: Is there a reason Dracula was able to walk in daylight, or did the filmmakers just ignore the whole "vampires can't walk in daylight" bit?
Answer: To add to the other answers, the "sunlight kills vampires" lore started with the 1922 German silent film, Nosferatu. The screenwriter wanted to add an unexpected twist to the story that differed from Bram Stoker's 1897 novel. It became the accepted vampire mythology in most films and books for many years after.






Answer: In Bram Stoker's novel on which the film is based, Dracula can be exposed to daylight, and while it diminishes his powers, it doesn't kill him.
Sierra1 ★
And the narrator specifically said that in the film.