Clo,
That was mentioned on the drive-time this morning and the person talking about it went into more detail with respect to what it was like around the Clinton White House (I think the person was part of the WH press corp at the time).
He said that when Hillary was out of town Bill would hold all-night policy meetings with his staff since this allowed him to concentrate on issues that he normally would have had to leave to staffers and since he was such a 'policy wonk', he felt this was when he could do his best work. It was also mention that this was a boon to the pizza parlors near by since he would personally order out and pay for pizza for everyone when he would hold these all-night sessions. The rumor was that the reason he took so few real vacations was that he felt it interfered with his ability to work on stuff with the people who were expected to either stay at the White House or be with him when he was on official business, but not when he was taking 'personal' time off.
I'm not sure what it was like at the White House, but when I was working in engineering back in the 70's, when the boss was on vacation it was like a mini-vacation in the office and we would look forward to those times. In fact, my first supervisor told me that the REAL reason that the bosses were allowed to schedule their vacation before the rest of us was allowed to was so that we wouldn't 'waste' ours by scheduling it for the same weeks that your boss had