My company has a shut-down over the Christmas holiday. I've been off work (paid!) since December 23. It was sooooooo nice to sleep in, stay in my jammies, and sew ALL DAY LONG. Nirvana.
Had to come back to work today. I've hit the 3:00 PM "wall" when you know that you're not going to do any more work today (barring a co-worker standing in front of you waiting for you to complete a task).
I think they should have "eased" us back into the work week schedule. 1/2 days for the first ... oh ... 4-5 months should work