What date to what date are the 12 days of Christmas?

The 12 days of Christmas, in fa­ct, are the days from Dec. 25, celebrated as the birth of Jesus Christ, to the Epiphany, celebrated on Jan. 6 as the day when the manifestation of Christ's glory was realized.

Of course the exact date of Jesus' birth is not known but the 25 December is when we celebrate it :-D