When Dick leaves the first meeting with Duval to fetch Jo from the café, he says he will have her there at 10 o'clock the next morning. He later tells Jo that she needs to be there at 10:30, which would make her late twice in a row.
At the end of the film, we see Dick leave an evening fashion show party to join Jo at the church for the final dance. But once the church scene begins, a hazy filter can't hide the fact that it was shot in broad daylight (complete with blue sky), even though it should still be evening.
After Dick kisses Jo and leaves the bookstore, Jo begins to sing "How Long Has This Been Going On". As she sings to herself while looking at the mirror in the supposedly empty bookstore, you can clearly see someone moving around on the second floor of the bookstore reflected in the mirror.