I went with a rainbow color scheme, with the cooler colors representing the colder temperatures and warmer colors being the warmer temperatures...and as you can see, we had a lot of warm days here in St. Louis, MO this past year!
Technical details: my rows were single crochet for week days and granny stitches for Saturday and Sunday. This ultimately made the blanket longer than the bed but it allows for some visual detail between the weeks. I used a size G hook (4mm) and the width is 288 stitches. On each of our families birthdays, I added a silver thread that I crocheted along with the color corresponding to the temperature of the day. For the most part, I crocheted over the tails when changing colors using the next row, except in the case where it was a granny stitch and I had to weave those in using a yarn needle. I did stitch back and forth from each end, whichever end I left off with the previous row. The border is two rows of single crochet, finished with a large shell border.