By the law of averages alone, I guess that must be right - but you'd be amazed at how many people think they work better at night when in fact, they don't. Musicians are probably the classic example.

When I was in my teens and twenties I used to work in a recording studio. We made a fortune from muso's who'd come in to record (at night). Then - when they heard themselves played back in the cold light of day - realised how god-awful they sounded and had to record the whole session all over again!!

Mind you... I don't suppose all the booze and spliffs helped much!