This is my way to get the 365 days achievement on the most easy way on PC.
First Things First
The in game mechanic counts all days You’re on the Raft. It doesn’t matter if You’re alive or not. And that’s the Point: You are not! I’ve done it by dying through the Days. At first, I emptied my inventory to make sure not to lose anything. My Raft was on free water and I put my Char in a Shelter to make sure not to get hit by a Screecher if I would hit an Island by accident.
Shut down Speaker and Monitor…
Make sure nothing goes wrong: Leaving Your PC alone could result a fire- This is not worth the achievement and this is Your responsibility!
Go to sleep, work, whatever…
Every 15 Minutes it changes between Day and Night. So depending on Your actual Day it needs plenty of hours without You Playing: 30 Minutes are one Day, 1 hour are two Days, 365 Days means 183 hours in game without sleeping. Sleeping descends that amount on 92 hours, but You need to be focused permanently and You need to be playing.
Step one finished? Stay calm and walk the Line! I targeted the Moment to be Alive to make sure it happens. It does not happen to Your Company if they do not have the same Amount of Days, keep that in mind.