month

Where does the word "month" come from? It comes from Proto-Germanic *mēnōþs, passing through Old English before entering English (1200s).

Month’s story begins in Proto-Germanic: *mēnōþs meant “month, moon.” From the same root as 'moon', since months were measured from one new moon to the next. By 725, the word had taken hold in Old English as mōnaþ. Bede's The Reckoning of Time (725) explains that the English 'anciently reckoned their months according to the course of the moon'. It reached English by 1200s as month. The calendar months of unequal length came from Julius Caesar's reform of 45 BC. Today, month means each of the twelve named periods into which a year is divided.

1. Stage 1 · Proto-Germanic · prehistoric *mēnōþs "month, moon", from the same root as 'moon', since months were measured from one new moon to the next.
2. Stage 2 · Old English · 725 mōnaþ "month", Bede's The Reckoning of Time (725) explains that the English 'anciently reckoned their months according to the course of the moon'.
3. Stage 3 · English · 1200s month "calendar month", the calendar months of unequal length came from Julius Caesar's reform of 45 BC.