I know I did a block similar to this one at one point this year. I'm going to have to dig through the enormous pile of blocks to see if I can find it. The reason I remember doing something similar to this is because I did the same thing I did today. I thought all day I had an easy block with nothing but half square triangles and that it would be a breeze. It was not a hard block to make, I just had to rethink it a bit. It is made with half square triangles and flying geese which means I couldn't attach the whole seam with the flying geese at one time.
The calendar had this one with a black pinwheel in the middle. I realize that would have created more contrast, but I like how you can see the X better when only two colors are used. This is block number 235 of 366 and it is a 10-inch block. Happy Stitching!! --Kristen