One of the first things Michael Bloomberg did when elected mayor of New York was install a new clock at the centre of his team's main office.
It was not a decision motivated by aesthetics or feng shui, but a brutally pragmatic, ever-present reminder of his diminishing window of opportunity.
Every year. Every month. Every second. Like a bomb in a Bond film, it counted down the remaining time Bloomberg had to change New York.
If Barack Obama has a similar timepiece, he could be mistaken for checking its batteries. For a President with three years still left to run, he is already enduring rampant public debate as to who will replace him in the White House come 2016 (this writer, I might add, is as guilty of speculating as any) and what contenders fancy their chances this far out from the election.
Of course, anyone with the arrogance to even suggest themselves as worthy of presidential office must also be concerned with how they will be remembered when their time is done. And this week, 50 years on from President John F Kennedy's death, the ticking seconds on Obama's second-term clock were falling faster than ever.