tous les 15 jours

== French == === Etymology === Literally, “fifteen days”. Possibly originally a Celtic concept; compare the etymologies of Welsh pythefnos (literally “fifteen nights”) and Irish coicís (literally “fifteen”). === Pronunciation === IPA(key): /kɛ̃z ʒuʁ/, /kɛ̃ʒ‿.ʒuʁ/ === Noun === quinze jours m pl (plural only) a fortnight, a period of two weeks, of fourteen days (exactly or approximately) dans quinze jours ― in two weeks tous les quinze jours ― once a fortnight; fortnightly Ça fait quinze jours que je ne l'ai pas vu. ― It's been two weeks since I last saw him.