I personally have no opposition to recognizing the amount of time that has passed since I was a drinker, because alcohol has been squarely set as "never an option", but for some people counting can be a problem. Many propose that it is our Addictive Voice that counts time, and can "use" that as a reason to return to drinking/using (as in, "Look how long you've gone! We deserve a drink!" or "It's been so long, I can handle just a few now."
I think about a particularly abusive ex from time to time and I really have to think hard about how long it's been since I made the decision to cut contact with him completely. After a long struggle, I quit him completely and left the pain behind, and never looked back. I don't count daily how long it's been. To me, that would indicate that he still had a hold on me or that I still entertain that relationship on some level. I think of my addiction in the very same terms. Never going back there again, so I give it the level of mental energy that it deserves. Exactly zero.