So a few days ago, we tweeted this:
It sounds odd, but it’s completely true. Noon is a corruption of the Latin nona hora, or “ninth hour”, which in turn has its roots in the Latin word for “ninth”, novem, as in November. And just as November was originally the ninth month of the Roman year, noon was originally the ninth hour of the Roman day. And because the Romans are reckoned to have started their day at 6am, this made noon 3pm—or the ninth hour of daylight.
This mid-afternoon meaning was retained when the word noon first began to appear in English in the early Old English period. The OED has traced the word’s earliest written record to a medical textbook dating from the ninth century, which, under a remedy used as protection “against witches and elvish tricks”, describes a concoction of milk blended with powdered blackberry, lupins and pennyroyal that should be drunk “on þreo tida, on undern, on middæg, on non”—that is, “three times a day, at undern [9am], midday [12pm], and noon [3pm]”.
In fact noon didn’t come to refer to 12pm until the early 1200s. So what prompted the change from one time of day to the other?
Well, admittedly no one is quite sure, but the most likely explanation is an ecclesiastical one: around the same time, traditional church prayers shifted from mid-afternoon to midday, and it’s possible that the word noon simply shifted with them. Alternatively, there could have been a cultural shift responsible, that saw working hours change after the Norman Conquest and the main meal of the working day brought forward from mid-afternoon to closer to midday.
Whatever the reason, the change seems to have firmly established itself in the language by the late 1400s, by which time the original literal meaning of noon had all but vanished to be replaced entirely by the meaning we know and use today.