A sober birthday is the day that marks the end of a person’s addiction. Some individuals will use the last day that he or she used drugs to mark his or her sober birthday, or the day after the last time they used.
Most of all, a [sobriety] birthday (also known as a sobriety anniversary, sober anniversary, recovery anniversary, or sobriety [milestone]) also serves as a reminder of the progress you've made, and the [new life] an addict has chosen for themselves.
Sean Ward
Because he has to do something in his free time
