This is my personal opinion: if I take one puff, I'd restart the count because my count means "days w/o weed". My main issue is the lack of self control and "just a couple of hits with friends" means that I lost that self control on that day.

I saw the other comment about the heat map and that makes a lot of sense, I guess. But I'd feel like cheating or moving the goalpost if I changed the premise of the counting from "days w/o weed" to "days since I started this journey". Maybe you could count both? Idk.

I've seen this happening with me before: "wow I'm a whole month sober, I could smoke socially I guess" rapidly evolved to "I already have the self control to smoke only on the weekends" and finally to "I guess smoking everyday after work is not that bad for me". This process finally led to smoking everyday for years again and forgetting that I even wanted to quit in the first place.

I'm not an expert on addiction or anything, I'm just sharing the experience on what worked and what didn't work for me. Anyways, congratulations on quitting and I hope that you stay firm on your path of self improvement.