Where did they come from? In fact, it was an earlier US president who got the 100-day bandwagon rolling. When Franklin D Roosevelt entered the White House in the wake of the Depression of the early 1930s, he instigated a radical 100-day plan to reform the failing US economy. Talk about a 'burning platform' for change! Crucially, he inspired a sceptical nation with his leadership and bold rhetoric - 'I tell you we have nothing to fear except fear itself', and so on. Ever since, new leaders have found their efforts judged at the 100-day landmark. Artificial, perhaps, but irresistible.
Where are they going? New leaders will never be able to escape this 100-day litmus test. Gordon Brown was merely the latest new boss to set himself the deadline. Luckily for him, terrorist attacks and natural disasters arrived to make sure he had an action-packed (and successful) start to his premiership. Perhaps that is the secret: next time you find yourself starting in a prominent role, make sure you set up a few easy quick wins - but be certain to make them look as difficult and nightmarish as possible.
Fad quotient (out of 10) 100... oh, all right, eight.