Nychthemeron , occasionally nycthemeron or nuchthemeron, is a period of 24 consecutive hours. It is sometimes used, especially in technical literature, to avoid the ambiguity inherent in the term day.
It is the period of time that a calendar normally labels with a date, although a nychthemeron simply designates a time-span that can start at any time, not just midnight.
Etymology It is a loanword from Ancient Greek (), which appears in the New Testament. This is a noun use of the neuter singular form of , from (, “night”) + (, “day”). In other languages Some languages have a word for 24 hours, or more loosely a day plus a night in no particular order. Unlike a calendar date, only the length is defined, with no particular start or end. Furthermore, these words are considered basic and native to these languages, so unlike nychthemeron they are not associated with jargon.
Words for 24 hours are listed in the third column. For comparison, the word for day, in the meaning of daytime, the sunlit state, the opposite of night, is also listed in the rightmost column: Language Family 24 hours Sunlit state Latvian Baltic diennakts ("day-night") diena Lithuanian Baltic para diena Swahili Bantu siku mchana Welsh Celtic ; ('that day') Danish Germanic døgn dag Dutch Germanic etmaal dag Faroese Germanic samdøgur dagur German Germanic Etmal Tag Icelandic Germanic sólarhringur ("sun-circle") dagur North Frisian Germanic eetlem däi Norwegian (Bokmål) Germanic døgndøgn in Bokmålsordboka dag Norwegian (Nynorsk) Germanic døgn,døgn/døger in Nynorskordboka døgerdøgn/døger in Nynorskordboka dag Old Norse Germanic dǿgr, dǿgn dagr Swedish Germanic dygn dag West Frisian Germanic etmel dei Yiddish Germanic ֵמֵעֵת לְעֵת טאָג Bengali Indo-Aryan দিনরাত, অহর্নিশ দিন Sanskrit Indo-Aryan अहोरात्र दिन Esperanto International auxiliary language diurno,diurn/o in Reta Vortaro tagnoktonokt/o in Reta Vortaro ("day-night") tago Japanese Japonic 日 昼 Kannada Kannada–Badaga ದಿನ ಹಗಲು Georgian Kartvelian დღე-ღამე ("day-night") დღე ("day") Korean Koreanic 일 낮 Indonesian/Malay Malayic hari siang Hebrew Semitic יממה יום Bulgarian Slavic денонощие ("day-night") ден Polish Slavic doba dzień Russian Slavic сутки день Ukrainian Slavic доба день Tamil Tamil நாள் பகல் Estonian Uralic ööpäev ("night-day") päev Finnish Uralic vuorokausi ("turn-period") päivä North Sámi Uralic jándor beaivi
The word , as in the Nordic languages, is etymologically the same as day in English.
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