Midday and Noon Were Once Three Hours Apart
Midday is the middle of the day. Noon originally meant the ninth hour, which was mid-afternoon.
Midday is the middle of the day, around twelve o'clock. Its synonym *noon* did not start there: it comes from Latin *nona hora*, the ninth hour after sunrise, which was around three in the afternoon. The monastic office said at that hour gradually moved earlier, and the word moved with it until noon meant midday.
- The middle of the day. *The midday sun.*
- Noon — the same time. *Twelve noon.*
- Meridian — the line the sun crosses at noon. *Local meridian.*
Word forms
| Form | Word | Example |
|---|---|---|
| Noun | midday | At midday. |
| Related | noon | Twelve noon. |
| Related | forenoon | The forenoon. |
| Related | afternoon | This afternoon. |
| Related | meridian | The prime meridian. |
How it is used in a sentence
- Noon once meant three in the afternoon.The ninth hour.
- AM means before midday.*Ante meridiem*.
- Solar noon differs from clock noon.Except on the exact meridian.
Time words from Latin
- AM — *ante meridiem*, before midday
- PM — *post meridiem*, after midday
- Meridian — the north-south line the sun crosses at noon
- Noon — from *nona hora*, the ninth hour
- Matins, vespers, compline — monastic offices that shaped the daily rhythm
A compound of *mid* and *day*, both Old English. *Noon* came from Latin *nona hora*, the ninth hour.
Why did noon move?
The monastic office of None was gradually observed earlier, and the word for the hour moved with the practice until it settled at midday.
Is twelve noon AM or PM?
Neither, strictly. It is the meridian itself. Twelve noon and twelve midnight are the unambiguous terms.