de longue date

long-standing

→ de
phrase Rare #52,055
long-standing Also used with verbs such as connaître to mean “for a long time.”
FR: C’est un ami de longue date.
EN: He’s a longtime friend.

Il s'agit d'un problème de longue date.

This is a longstanding problem.

Un homme d'une haute intelligence, je le connais de longue date.

A man of great intelligence, I have known him for a long time.

— Guerre et Paix (1968)

Alexandre Loukachenko est le dirigeant de longue date de la Biélorussie.

Alexander Lukashenko is the long-time leader of Belarus.

Non, mais avec un rabais client de longue date.

No, but with a long-standing customer discount.

— Roma (2018)