Your timeline profile on Facebook will now show a little clock symbol for publishing your status updates. If you click on the clock, you can type in the year, and then the day and month fields. Your post will be placed in its correct spot in your timeline.
The past posts in your timeline don't have the clock icon yet, but it should be coming soon. This should further help you manage your own story online, as you can add depth with the addition of more and more posts.