post diem
/ˌpəʊs(t) ˈdiːɛm/Now rare
adverb
After the due date, after the time in question; usually in the context of litigation about debt.
Origin
Early 17th century (in an earlier sense). From post-classical Latin post diem (in e.g. solvit post diem) from post after + diem, accusative of diēs day.