Twelfth Night is technically January 5th, the eve of Epiphany, although many in the modern world (like me and others in New Orleans) celebrate Twelfth Night on the evening of the twelfth day of Christmas, rather than on the eve of it, i.e. the evening before.
Soooo, while all of my information states that Joan's birthday is Twelfth Night...technically her birthday is the Ephiphany...but blame the modern world....
For additional info about Twelfth Night, Epiphany, and all things related, visit the links below.
Twelfth Night is a holiday in some branches of Christianity marking the coming of the Epiphany, concluding the Twelve Days of Christmas, and is defined by the Oxford English Dictionary as "the evening of the fifth of January, preceding Twelfth Day, the eve of the Epiphany, formerly the last day of the Christmas festivities and observed as a time of merrymaking".
The celebration of Epiphany, the adoration of the Magi, is marked in some cultures by the exchange of gifts, and Twelfth Night, as the eve or vigil of Epiphany, takes on a similar significance to Christmas Eve.
In some traditions it is taken to mean the evening of the Twelfth Day itself, the sixth of January. This apparent difference has arisen probably because in modern times people are less aware of the old custom of treating sunset as the beginning of the following day, and perceive Twelfth Night to mean the night of the Twelfth Day