köken: From long + temps, from Old French lonc tans. Ultimately inherited from Proto-Indo-European *dlongʰos, which is also where the English long time came from. The French term is a partial cognate, not a calque, of the English one.
aile: avant longtemps, de longtemps
Ça fait longtemps que ton frère habite chez toi ?
C'était comme ça il y a longtemps, mais plus maintenant.
köken: First attested in the Seokbo sangjeol (釋譜詳節 / 석보상절), 1447, as Middle Korean 오래〮 (Yale: wòláy), originally a derived adverb of Middle Korean 오라〮다〮 (Yale: wòlá-tá, “to be a long time”) with adverbial suffix 이 (Yale: -i), but rarely perceived as such by modern speakers.
köken: Instructive singular case of the root kauka- (kauko-) (“far”) (*kauɣan). Cognate to Ingrian kavvan (“for a long time”), Estonian kaua (“for a long time”), Votic kauga (“for a long time”).
long, a long while, a while, for long, for a long time · continually, all day · long enough
zıt: paulisper, noctū, nocte, nox
köken: From Proto-Italic *djowe, from Proto-Indo-European *dyéw(i) (“during the day”), locative case of *dyḗws, with d possibly imported from diēs. Cognate with Old Armenian տիւ (tiw), Sanskrit दिवा॑ (dívā, “by day”), ज्योक् (jyok, “for a long while”).
köken: From Old Norse lengi, originally an accusative of the noun Old Danish længe (“length”), from Proto-Germanic *langį̄, cognate with German Länge and Gothic 𐌻𐌰𐌲𐌲𐌴𐌹 (laggei). Derived from the adjective *langaz (“long”).
Etymology tree Proto-Indo-European *delh₁gʰ- Proto-Indo-European *dl̥h₁gʰós Proto-Balto-Slavic *dílˀgas Proto-Slavic *dь̀lgъ Old Polish długi Proto-Slavic *-o Old Polish -o Old Polish długo Polish długo Inherited from Old Polish długo. By surface analysis, długi + -o. Compare Czech dlouho, Kashubian długò, and Russian до́лго (dólgo).