I know it's a day off, but I find that the nicest thing about holidays is that there are no college students hanging around outside my office. Although I do take the opportunity to sleep in, I am convinced that the best way to use this time is to take a free research day.
And I think this is especially true for those of us without a tenure-track job. And for those of us who did not snag an on-campus interview this year. One of the most frustrating things about the academic job market is that it's on this annual cycle. If things don't work out this time around, it's going to be October before another tenure-line job ad comes out.
The only constructive way to handle it is to use the year to your advantage. We've got until the middle of October to put ourselves in position to do better.
Also, God damn it.