Apparently, that is today, if this discussion site can be relied upon.. I have no idea how long it has been celebrated, but the date was selected because it is also the feast day of St. John Bosco, who happens to be the patron saint of magicians. As a young man, John Bosco was something along the lines of a street performer. He could perform as an acrobat and a juggler, as well as doing sleight of hand and card tricks. You can find out a bit more about him here.
There are Christian and Catholic Magicians' guilds who follow in the footsteps of Don Bosco, and use magic and card tricks as a way of spreading the Faith. Here is a rather neat little video along those lines: