UPDATE 4: After 344 hours, I finally have the Lifer achievement.
UPDATE 3: After a long 291 hours, I finally have the Day Three achievement.
UPDATE 2: It took me 258 hours to get the Day Two achievement.
UPDATE: Ok, so the this achievement just unlocked for me at random on the menu. I've played for 220 hours, so it's more buggy than unobtainable.
This achievement is currently broken, but a dev said a fix is coming.
Once these achievements are fixed, simply play the game for 168 hours total to get all four achievements. Hopefully, it unlocks retroactively.
Playing for 168 hours should unlock: