I think it is important to give ourselves credit where it is due... Periods of abstinence are great. That said....
I learned the most about myself when I REALLY wanted a drink and did not have it. That is where I gained my confidence. Slips here and there just undermined my confidence.
I was the "relapse queen" for a long time and what that did was convince me I was not capable of quitting. Now I am learning that is not true.
It is funny you talk about the calendar with the colored squares. I used to keep a calendar by my bed and put an X on everyday I didn't drink and fill in the box on days I did. I was very happy at the end of the month when I had more X's then filled in days. That was my goal back then. As my goal changed I no longer do that.
I can only live in "the now" though. If I allowed myself to relapse tomorrow then would I be a failure? Well, I would have failed at my goal but, there are many other aspects to my life that I would be successful at. Also I definitely agree that you have to keep trying NO MATTER WHAT.