The best time on a clock is 6:30, hands down.

Behind the Groan

Picture Both Hands Pointing Down

“Hands down” means unquestionably, making it a natural way to declare one choice the best. At 6:30 on an analog clock, the minute hand points straight down and the hour hand points downward between six and seven, giving the idiom a visible second meaning. Say “6:30” clearly enough for listeners to picture a clock face, then let the final phrase follow without a dramatic pause. The joke works fastest when the familiar expression prompts the image on its own.