Agreed Eulalia, I always thought that 12th night occurred on Jan 6th. but I've been wrong before.Twelfth Night is the evening of Jan 5th (the first day of Christmas is Christmas Day)
The Epiphany is Jan 6th.
Orthodox (Julian Calendar) Christmas begins on the evening of the 6th, Christmas Day is the 7th.
At least, that's the 'ecclesiastical' position.
in the secular world there seems to be a fair amount of variation.
Shall we settle on the 7th?