This achievement, despite its picture, its description, or even its name has absolutely NOTHING to do with sleeping. Even the "myxer" solution has nothing to do with sleeping. You don't need a sleeping bag, you dont need a raft, you dont need a camp. On day 108 I got tired of sleeping on my raft over and over again and upon reading the "myxer" solution it got my wheels spinning. They changed the day and night cycle eh? I thought, well it says "dont sleep on land"...so I literally just didnt sleep...on my boat, on land, anywhere. Its a huge pain to not be able to run for 8 days but in the end, on your 9th day, at the stroke of midnight it will pop. The "myxer" solution only works because they are basically fast forwarding you several days in a short period and you arent sleeping. If you try sleeping during that fast forwarding it will still fail. I'm glad i figured it out because the frustration was real after trying this for probably 80+ nights of raft lounging.
I hope this helps.