The Original Sudoku 2015 Page-A-Day Calendar

Every day, pit your wits against a master’s. Now in its tenth successful year, The Original Sudoku Calendar offers hundreds of full-color puzzles that are made by hand—not by a computer—and are unmatched in their elegance and appeal. They begin easy each weekend, and increase in difficulty over the course of the week. From Nikoli, the Japanese company that rediscovered Sudoku, these puzzles strike the perfect balance of challenging and fun.