What Happened on the Day Before the Feast of All Saints in 1517?

Did you know that Martin Luther (the original) chose to perform his courageous deed on Marash Girl's birthday (many centuries earlier, of course) and it took her this long (a lifetime) to find out?  "On October 31, 1517, the day before the Feast of All Saints, the 33-year-old Martin Luther posted 95 theses on the door of the Castle Church in Wittenberg, challenging the Roman Catholic Church."  A courageous deed in deed . . . a deed unequaled in its time or possibly since!