I always thought Advent Calendars with 24 doors are outdated. Something like 300 feels more appropriate ;-)

Fixed :)

Advent Calender 2014: Double Dutch Sudoku Advent.

Richard Stolk wrote:
We would like to inform you all about a unique Sudoku advent calendar that I created together with my good friend Arvid Baars for the puzzle portal of Logic Masters Germany. We have chosen 12 very well known sudoku variants and 12 much less known variants. Every day we combine two of these in the schedule AB - BC - CD - ... - LM - MA. We believe that combining variants leads to very interesting solving steps, which really adds to the solving fun. We provide solving hints every day too, that might help you getting started.