I grew up with Advent Calendars , and they are very common in the UK. Shops across the country sell calendars with typically 24 doors on them, one for each day from December 1 to December 24. Behind each door is a small gift (usually chocolate or something similarly sweet and edible). The numbers on the doors of the calendar are usually arranged somewhat haphazardly. Part of the fun each day is finding the next door to open. It's the search for the chocolate that makes the calendars enjoyable. Here's an example layout from an Advent Calendar that I bought in Paul in London: This is an example of a very common 6x4 (and sometimes 4x6) layout for calendars. In this blog I'm going to develop code to find "pleasing" Advent Calendar layouts in the 6x4 shape. But first, here's a little animation of the Paul calendar in action. What makes it "pleasing" is that the numbers don't cluster together (mostly). So, that calendar isn't