The first time exABF stopped drinking, unassisted by a program, any time *he* brought it up to me, "Hey, it's been 30 days!", I would respond with a 'way to go' but nothing really more than that. I was genuinely thrilled for him that he could physically do it.
I have a childhood friend who just celebrated her one-year chip, and I did send her a birthday card and it wasn't her belly-button birthday! Pretty cool to share that time with each other, since she shares so much of her recovery with me.