From 1964, when John Lennon and Paul McCartney were writing hit songs for fun. Only released as a single in the USA, where it reached number one on on March 13 1965.
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Paul McCartney has attributed the inspiration of the song to at least two different sources. In a 1984 interview with Playboy, he credited the title to Ringo Starr, who was noted for his malapropisms, which are credited as the source of other song titles (such as "A Hard Day's Night" and "Tomorrow Never Knows").
LINDA: Ringo also said, 'Eight days a week.'
PAUL: Yeah, he said it as though he were an overworked chauffeur. (in heavy accent) 'Eight days a week.' (laughter) When we heard it, we said, 'Really? Bing! Got it!'
—Paul McCartney & Linda McCartney, 1984 Playboy Interview
However, he has also credited the title to an actual chauffeur who once drove him to Lennon's house in Weybridge.
I usually drove myself there, but the chauffeur drove me out that day and I said, 'How've you been?' – 'Oh working hard,' he said, 'working eight days a week.'
—Paul McCartney, The Beatles Anthology
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