Casual Friday: Why don't they make writing calenders?

It seems like every store I've gone in lately has calenders on sale. I've already gotten a cheap one from the dollar tree, so I barely glance at them, but today I decided to take a look. There were calenders of every kind, but there was one type I've never seen: a writing calender. Wouldn't it be cool if there were a writing calender with a writing prompt each week or month?