Thought at first you were talking about the French not working!
France has weird and wondrous opening and closing hours for many things so here's a list of the ones I can remember:
Most shops including supermarkets are usually closed on Sundays and feast days like Bastille Day, Pentecost etc. However some shops may be open on Sunday morning depending where you are.
Small supermarkets are often open in the morning.
Some larger ones are now starting to open for the whole of Sunday.
All shops will be fully closed on Mondays except supermarkets and bakers.
All shops are closed at lunch time between 12.00 and 15.00 but again this can vary. Large supermarkets are always open at lunch time but may be inhabited by Brits!
Campsite offices may be closed during this period too. Its usually OK though to put your van on on an 'emplacement' during this period providing you can get through the barrier.
Some filling stations are shut on Sundays, but all are open on Autoroutes.
Restaurants are often closed on Tuesday evening and the whole of Wednesday! They usually have at least a day and a half off during the week.
Bars in towns will possibly stay open in the late evening but not usually after 22.00 hrs.
Schools often close on Wednesday afternoon and are open on Saturday mornings.
Times of openings of shops are usually posted outside them - look for the word 'Horaires'.
And from July to the beginning of September this all goes to pot as many of them are taking their 'Cong