The Twelve Days of Sacksmas coincide with the Twelve Days of Christmas. The first card will become available on the 25th or 26th (forget which one). The last card becomes available, and Penstock’s opens, on the 5th or 6th of January. It them stays open through the end of January, more or less.
The Urchins handing out pails of snow is more variable. Not sure on that one, sometime within the next week maybe?