A Jew who has a court case with a non-Jew should postpone it...

Nshei Chabad Newsletter / For the same reason (see the last Halacha), a Jew who has a court case with a non-Jew should postpone it, if possible, until after the entire month of Av, but at least until after Tisha B'Av (Kitzur Shulchan Oruch, Ch. 122, Par. 7).