I don't know specific dates..
My mom went to rehab when I was little. I have no idea how long she was sober. She then drank socially for many years (at least 10??) She then started to going to AA after a health scare and the REAL extent of the drinking came out. She was sober for a year or two and then relapsed getting in a car wreck. AA again.. probably another year or so sober. Small relapses in between and now attends AA seven days a week. I know she's been sober for months maybe 8 or 9, but I don't ask. She does seem very happy and I'm super proud of her. We have remained best friends through it all.
My Biological Father (we've never been real close) has had periods of sobriety on and off for years as well. Mostly forced I suspect. Either because bars have kicked him out, limited him to two beers, he's been so heavily medicated that he can't drink, or in and out of prison. Pick your poison I guess. I haven't spoken to him but I hear he's back in prison on his 6th DUI.
The A I live with has never sought sobriety and doesn't feel the need to.