There is usually at least one day of the week where Louvre opening hours extend; at the moment it appears to be open until 9:45 p.m. on Fridays. That is right in the middle of Parisian dinner hours, and it is a wonderful time to meander through the capacious and ornate halls in the quiet amongst much fewer people than you’ll find in the morning and afternoon hours. I went one May evening from about 7:30-9 p.m., and it was my most memorable visit.