As the first day of May is a Labor Day holiday in France and working on this specific day is subject to stringent legal restrictions, Blizzard Europe will be providing limited support on Thursday, May 1st. All the realms will be available for play as usual, however our Technical and Billing Support teams will not be able to respond to your queries on this day.
Our Game Masters will be working all day and night, but in a reduced capacity so you may experience a slight delay in the response time to your in-game tickets. We apologize for any inconvenience caused and thank you for your understanding.
Original post by World of Warcraft Community Site