faire le pont

to stretch a public holiday into a long weekend

The trick of stretching a single public holiday into three or four days off, by also taking the one working day in between.

Comme jeudi est férié, toute l'entreprise fait le pont vendredi.

Since Thursday is a public holiday, the whole company is taking Friday off too.

Already had its current meaning when it appeared under the Second Empire in the mid-1800s, the image being that a single day off spans the gap between one riverbank and the other, like a bridge.