Noon used to be at about three in the afternoon. The word comes from the Latin nona hora, the ninth hour counted from sunrise, and in monasteries it was the hour of a service, nones, before which nobody ate on a fast day. Somewhere between the twelfth and fourteenth centuries the word slid back to midday. Nobody is sure why: medieval clocks were unreliable, and an hour of daylight was a different length in winter and in summer. But the explanation I like best is the hungry one, that the ninth-hour prayers kept getting said a little earlier, until the ninth hour arrived at the sixth. If that’s right, it is the only time of day I know of that was moved by appetite, and it never moved back.