People have to go to work or school on weekdays. But families have more options about their activities on weekends. Having a day or two to keep your kids near while you get used to the idea of sending them off on Monday might give everyone a chance to get used to the war and to implement any extra safety precautions needed.
Then, again, I know the first consideration has to be what's best for success in the Iraq theatre, so maybe I'm wrong.
But one thing that I do not believe is that they will give him 48 hrs. notice.