Chevalier de la Barre Day - July 1
From Secular Seasons
: "Mainly a French observance, Chevalier de la Barre Day is a day that can be celebrated by anyone who opposes religious oppression. The annual commemoration marks the execution of the Chevalier de la Barre for impiety on July 1, 1766.
Jean-Francois de la Barre (known as the "Chevalier de la Barre", because he held the formal title of Chevalier or "knight") became a symbol of religious injustice after being tortured and killed for impiety, including the possession of banned books by Voltaire."
More via Wikipedia
: "Jean-François Lefevre de la Barre (September 12, 1745 – July 1, 1766) was a French nobleman, famous for having been tortured and beheaded before his body was burnt on a pyre along with Voltaire's "Philosophical Dictionary". He is often said to have been executed for not saluting a procession, but the elements of the case were far more complex. In France, he is a symbol of Christian religious intolerance, along with Jean Calas and Pierre-Paul Sirven, all championed by Voltaire. A statue to him stands in the Montmartre district of Paris and a street nearby is also named for him."
I dread to think of all the things I've done much more blasphemous than not taking off my hat when a religious procession passes by.