Holiday on Ice

I understand GWB is still on holiday, which started me thinking:

How do they calibrate these things? Similarly, how do they know when he's back, and no longer on holiday?

The answer just occurred to me: Barney stands at a point. I knew Barney was the key after recalling Gertrude Stein's brilliant, "I am I because my little dog knows me." There can be no other definitive identifier for when GWB has actually returned to the job. I'm sure that Barney, like most dogs, is a dutiful sentry. One must have faith in something.