You can't really day count for codependency...
It's not like quitting an addiction (where you can count days), or starting an exercise program (where you can physically track your weight loss, or how often you have gone)...
It's more of whether or not you take care of yourself, or stand up for yourself in unhealthy situations, and how you feel about it when you're doing it.
It's a change in your whole personality, which means it's harder, but oh so rewarding when you're working on it.
How well a person is "recovering" from co-dependency is, essentially, another measure of their mental health and well-being. It's hard to measure.