I wrote the letter on September 1st, so we'll send you back the very next day, September 2nd. That's a Wednesday.

4 seconds sound clip from the Back to the Future Part III movie soundboard.

You can hear this line at 00:17:20.965 in the DVD version of the movie.

Quote context

[...]

- This was all completely open country, so you'll have plenty of run out space when you arrive.

- Remember, where you're going, there are no roads.

- There's a small cave over there which will be a perfect place to hide the time vehicle.

- Well, the new time circuit control tubes are warmed up.

- Time circuits on.

- I wrote the letter on September 1st, so we'll send you back the very next day, September 2nd. That's a Wednesday.

- September 2nd, 1885, 8:00 a.m.

- I get shot on Monday the 7th, so you have five days to locate me.

- According to my letter, I'm a blacksmith, so I probably have a shop somewhere.

- All you have to do is drive the time vehicle directly toward that screen, accelerating to 88 miles an hour.

[...]