I always find it best to prepare for the next day if I've done everything I can for now--more curios, make sure i have food ready, etc. If you've got an hour to kill today, it'll save you an hour tomorrow.
Otherwise... yeah, not much else to do but log out and play something else for a while. Of course, once you start building a fence, mining, etc. that will become quite the opposite as there will always be yet one more chore that needs getting done.