Note that the Christmas Fair is open on Christmas Eve, Christmas Day and also the 2nd day of Christmas. Although technically ending on December 26th, the Holiday Fair actually continues until January 6th. The only thing that happens on the 26th is that the name of the fair becomes the 'New Year's Fair' and things keep on rolling in the same spirit until January 6th.
With all the events taking place during Christmas in Krakow we have a more comprehensive list of all things taking place around the city.
10:00–20:00 Nov 29 2019 - Dec 26 2019