On one Saturday in May the museums stay open into the night and stop charging. In France around 3,000 institutions take part, from the Louvre to a single-room municipal collection in a sous-préfecture, and the programme is deliberately unlike daytime visiting: concerts in sculpture galleries, torchlit tours, workshops, actors planted among the exhibits.
The French ministry launched it in 2005 out of an earlier spring opening, and it was adopted across the Council of Europe; it now runs in some thirty countries on the same night, which is why the French figures and the European ones are often confused.
The ministry's last widely cited French figure is around a million visitors, from 2021 — a year when attendance was still shaped by the pandemic, which is why we record the year as prominently as the number. It should be treated as an order of magnitude.
It is anchored to the Saturday nearest 18 May, International Museum Day. The large Paris institutions queue heavily from nine o'clock; the pleasure of the night is in the small museums that are never open after dark.
PlanningAnchored to the Saturday nearest 18 May, so the date moves within a week but the weekday never does.