Fortnight — From Old English to English | etymologist.ai
fortnight
/ˈfɔːt.naɪt/·noun·c. 1000 CE in Old English; attested in the phrase 'fēowertyne niht' in the Anglo-Saxon Chronicle and related texts. The contracted form 'fourteniht' appears in Middle English by the early 13th century, with 'fortnight' fully established by the 15th century.·Established
Origin
From OldEnglish fēowertyne niht (fourteen nights), fortnight preserves the ancient Germanic custom of reckoning time by nights rather than days — a practice documented by Tacitus in AD 98 and embedded across the Germanic languages.
Definition
A period of two weeks, derived from Old English fēowertyne niht meaning 'fourteen nights', reflecting the ancient Germanic practice of reckoning time by nights rather than days.
The Full Story
Old Englishc. 900–1100 CEwell-attested
The word 'fortnight' derives from OldEnglish fēowertyne niht, literally 'fourteen nights.' The Germanic peoples measured time by counting nights rather than days — a practice explicitly documented by Tacitus in Germania (c. 98 CE), who wrote: 'nec dierum numerum, ut nos, sed noctium computant' ('they count not by the number of days, as we do,
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Tacitus noted in his Germania (AD 98) that the Germanic tribes counted not days but nights — nec dierum numerum sed noctium computant. This night-first reckoning survives in 'fortnight' itself. Americans largely abandoned the word in favour of 'two weeks', while British, Australian, and Commonwealth English kept it; a single vocabulary difference that marks a genuine cultural divergence in tolerance for inherited Germanic compactness
week — now archaic but attested well into the Early Modern period. The Proto-Germanic components are *fedwōr-tehun (fourteen, composed of *fedwōr 'four' + *tehun 'ten') combined with *nahtiz (night), the latter descending from Proto-Indo-European *nekwt-, the common ancestor of Latin nox, Greek nyx, and Sanskrit nakt-. In Old English, the phrase fēowertyne niht underwent progressive phonological reduction through the Middle English period. The medial unstressed syllables eroded, and by around the 13th–14th centuries, forms like 'fourteniht' and 'fourtenight' appear. The /r/ and /t/ cluster then underwent assimilation and further compression, yielding 'fortnight' by the late Middle English period. The word remains standard in British and Commonwealth English (e.g., 'paid fortnightly') but has largely fallen out of everyday American English, where 'two weeks' is preferred. The survival of the night-counting idiom in English, long after Germanic tribes converted to Christianity and adopted Roman calendar conventions, testifies to the conservatism of temporal vocabulary. Key roots: *nekwt- (Proto-Indo-European: "night; darkness"), *kwetwer- (Proto-Indo-European: "four"), *nahtiz (Proto-Germanic: "night"), *fedwōr-tehun (Proto-Germanic: "fourteen (four-ten)").