Regarding the origin of "Yesterday", Paul admitted that the tune came to him in a dream while he was living with Jane Asher (his girlfriend at the time) in her family's house in London. "I was living in a little flat at the top of [the Ashers'] house and I had a piano by my bed. I woke up one morning with a tune in my head ... I went to the piano and found the chords to it ... It just came to me in a dream" (Anthology, page 175).
The exact date of Paul's move-in with the Ashers is unknown, but thanks to McCartney's friend and biographer Barry Miles, we do know the month: "In November he moved out of Green Street and took his few belongings to the Asher household" (Miles 1997, page 104). We do, however, know that the Beatles' schedule during November 1963 was grueling: 26 live performances in 30 days. The only days that month that the Beatles did not perform live were November 8, 11, 12, and 18, making those four dates likely candidates for the move.
Of course, just because Paul would have played a concert on a particular evening does not necessarily mean that he could not have moved in on that same morning. But since the Ashers lived in London, it is probably safe to assume that Paul did not move on a day of a performance not in London due simply to travel. (Admittedly, Miles does make a point of stating that Paul's belongings were meager, so it is possible that he could have moved in the morning, traveled in the afternoon, and performed in the evening of the same day, but that seems unlikely.) On the other hand, two of the Beatles' November 1963 shows were in London (November 4 and 9), so it is reasonably possible that Paul moved in on one of those two dates, in which travel time would have been significantly less, and thus he would have had more time to do other things (like move) prior to playing a show. The only non-London performances within 100 miles of London during this month was Slough on November 5 (which was only about 25 miles from the Ashers' home in London) and Northampton the following day (which was about 70 miles away). Thus, November 5 and 6 can also be added to the possible move dates.
This brings the total potential move dates to 8: November 4, 5, 6, 8, 9, 11, 12, and 18.
- November 4 seems possible but unlikely because the Beatles played in Leeds (200 miles north of London) the previous day at 6 o'clock p.m. Given the late start time, it seems most likely that the band spent the night in Leeds and traveled back to London the following day (although, of course, it's possible they flew back after the Leeds show and Paul moved the morning of November 4).
- November 5 is almost certainly out because the Beatles were interviewed in the late morning and performed in Slough in the evening.
- November 6 is unlikely but possible because the Beatles performed in Northampton. I do not know where the band spent the previous night - in a hotel or at their apartment in London - but it seems the former would be more likely.
- November 8 would have been impossible since, although the band did not perform that day, they were in Ireland. There is no way Paul could have moved on the same day.
- November 9 seems like a very strong possibility since the Beatles performed in London that day.
- November 11 is extremely unlikely. Despite being one of the band's few off-days, they played the previous night in Birmingham (120 northwest of London), and had to cancel their booking the following day in Portsmouth (75 miles southwest of London, and 160 south of Birmingham) because Paul fell ill. It seems highly unlikely that Paul would have moved today between (1) he was getting sick, and what's more (2) the travel situation would only work by plane, and even if they were flying instead of driving, why wouldn't they fly Birmingham to Portsmouth directly?
- November 12 is almost certainly out because the Beatles were originally scheduled to perform that day in Portsmouth, but Paul fell ill and the show was cancelled.
- November 18 seems highly unlikely, too. Despite being another rare off-day, The Beatles played the previous night in Coventry and the following night in Wolverhampton - just 30 miles apart. Even with an off-day, it would make no sense for the band to travel 100 miles back to London, and then backtrack those same 100 miles plus an additional 30 to reach Wolverhampton two days later. It's possible, but not likely.
This weeding reduces the likely move dates to just one: November 9. Given this evidence (and admitting that this is hardly conclusive) it appears probable that Paul McCartney moved into the Ashers' house on the morning of 9 November 1963. What this means, then, is that the earliest possible date that Paul could have dreamed up "Yesterday" is 10 November 1963.
At this point, I should also mention that Paul often spent the night at the Asher residence prior to moving in there, and thus it is not unreasonable to think that perhaps he dreamed up "Yesterday" during one of those visits - prior to actually moving in with them. However it seems unlikely that Paul would have had a piano next to his bed if he weren't living there. And as quoted in Barry Miles' biography Many Years From Now, Paul said, "I eventually got a piano of my own up in the top garret. Very artistic. That was the piano that I fell out of bed and got the chords to 'Yesterday' on" (Miles 1997, page 114). This quote seems to show rather conclusively that Paul had in fact moved in to the Asher house before writing "Yesterday".
We also know that the earliest documented performance (in this case by "performance" I mean Paul played the song in its incomplete form) comes from a recollection of Lionel Bart citing "late 1963" (Spitz, page 560).
Thus, "Yesterday" must have been written between 10 November and 31 December 1963. Taking the next step of determining precisely what date "Yesterday" was born would prove utterly futile, but given that the band was out of town touring in early December, but played regularly in and around London in late December 1963, it seems more likely that Paul McCartney composed "Yesterday" in late December 1963 (when he was in London and thus staying with the Ashers more frequently) than in November or early December (when he was frequently on the road and thus not staying with the Ashers).
Several books cite May 1965 (Turner, page 83; Miles 1997, page 201) as the date of Paul's "Yesterday" dream. This is conclusively false. George Martin recalls first hearing the tune in January of 1964 (Lewisohn, page 59), as did Dick James and Chris Hutchinson (Carlin, page 94-95). Furthermore, John Lennon himself admitted that the tune "was around for months and months before we finally completed it" (Everett, page 300). This quote would make no sense had Paul written "Yesterday" in May 1965 - just one month before recording it in June 1965.
Peter Ames Carlin's biography of McCartney states that Paul asked for help identifying the song "First to the saloon singer Alma Cogan, then the theatrical composer Lionel Bart" (page 118). But the Beatles met Cogan for the first time on 12 January 1964 (Miles 2001, page 126), and Bart claims Paul played it for him in "late 1963" (Spitz, page 560). Clearly, the evidence is contradictory, and as a result, we may never know conclusively when Paul McCartney actually wrote "Yesterday". But given the available evidence, it seems most likely that Paul McCartney composed "Yesterday" in late December 1963.
Beatles. The Beatles Anthology. Chronicle Books, San Francisco, CA, 2000.
Carlin, Peter Ames. Paul McCartney: A Life. Touchstone Book, Simon & Schuster, New York, NY, 2009.
Everett, Walter. The Beatles as Musicians: The Quarry Men through Rubber Soul. Oxford University Press, New York, NY, 2001.
Lewisohn, Mark. The Complete Beatles Recording Sessions: The Official Story of the Abbey Road Years 1962-1970. Harmony Books, a division of Crown Publishers, New York, NY, 1988.
Miles, Barry. Paul McCartney: Many Years from Now. Henry Holt and Company, New York, NY, 1997.
Miles, Barry. The Beatles Diary, Volume 1: The Beatles Years. Omnibus Press, New York, NY, 2001.
Spitz, Bob. The Beatles: The Biography. Little, Brown and Company, Time Warner Book Group, New York, NY 2005.
Turner, Steve. A Hard Day's Write: The Stories Behind Every Beatles Song. itbooks, an imprint of HarperCollins Publishers, New York, NY, 2005.