On national holidays in France most shops and many public buildings and even tourist attractions can be shut. If you know where you want to visit check in advance to make sure it’s open on a French public holiday.
Many public museums and galleries are free to the public on the first Sunday of the month, though for some this is only outside of peak visitor times in the summer months, again, check in advance. You might find a few queues on those days as its a popular offering in France.
There are special celebration days in France too, though not national holidays: Celebration days in France
National Holidays in France 2019
January 1st (Tuesday) 2019 – New Years Day
April 22nd (Monday) 2019 – Easter Monday
May 1st (Wednesday) 2019 – Labour Day
May 8th (Wednesday) 2019 – V-E Day (Victory in Europe Day)
May 30th (Thursday) 2019 – Ascension Day : 40 days after Easter
June 10th (Monday) 2019 – Whit Monday : 7th Monday after Easter
July 14th (Sunday) 2019 – Bastille Day, French National Day
August 15th (Thursday) 2019 – Assumption Day
November 1st (Friday) 2019 – All Saints Day
November 11th (Monday) -2019 Armistice Day
December 25th (Wednesday) -2019 Christmas Day