From 11:00PM PDT on Friday, July 1 until 5:00AM PDT on Saturday, July 2, the Shmoop engineering elves will be making tweaks and improvements to the site. That means Shmoop will be unavailable for use during that time. Thanks for your patience!
There is a prayer hanging on the wall of Billy's office that says, "God grant me the serenity to accept the things I cannot change, courage to change the things I can, and wisdom always to tell the difference" (3.13.1).
Among the (many) things Billy cannot change are the past, the present, and the future.