the day before yesterday
Eles passaram por aqui anteontem.
They passed through here the day before yesterday.
— O Senhor dos Anéis: As Duas Torres (2002)
Eu me encontrei com ela por acaso no trem anteontem.
I ran into her by chance on the train the day before yesterday.
Anteontem foi terça-feira; depois de amanhã é sábado.
The day before yesterday was Tuesday; the day after tomorrow is Saturday.
I was there the day before yesterday.
Meus amigos me visitaram anteontem.
My friends visited me the day before yesterday.
Encontramos a mobilete onde ele passou a noite de anteontem.
We found the moped where he spent the night before last.
— Diva: Paixão Perigosa (1981)