Found the following article online, use it to answer the question: What was the date that recording was complete on Sgt. Pepper's Lonely Hearts Club Band? Sgt. Pepper's Lonely Hearts Club Band is the eighth studio album by the English rock band the Beatles. Released on 26 May 1967 in the United Kingdom and 2 June 1967 in the United States, it spent 27 weeks at number one on the UK Albums Chart and 15 weeks at number one in the US. It was lauded by critics for its innovations in production, songwriting and graphic design, for bridging a cultural divide between popular music and high art, and for providing a musical representation of its generation and the contemporary counterculture. It won four Grammy Awards in 1968, including Album of the Year, the first rock LP to receive this honour. In August 1966, the Beatles permanently retired from touring and began a three-month holiday. During a return flight to London in November, Paul McCartney had an idea for a song involving an Edwardian military band that formed the impetus of the Sgt. Pepper concept. Sessions began on 24 November at EMI's Abbey Road Studios with two compositions inspired by the Beatles' youth, "Strawberry Fields Forever" and "Penny Lane", but after pressure from EMI, the songs were released as a double A-side single and not included on the album. In February 1967, after recording the title track "Sgt. Pepper's Lonely Hearts Club Band", McCartney suggested that the Beatles should release an entire album representing a performance by the fictional Sgt. Pepper band. This alter ego group would give them the freedom to experiment musically. During the recording sessions, the band furthered the technological progression they had made with their 1966 album Revolver. Knowing they would not have to perform the tracks live, they adopted an experimental approach to composition and recording on songs such as "Lucy in the Sky with Diamonds", "Being for the Benefit of Mr. Kite!" and "A Day in the Life". Producer George Martin and engineer Geoff Emerick helped realise the group's ideas by approaching the studio as an instrument, applying orchestral overdubs, sound effects and other methods of tape manipulation....
The answer to this question is:
21 April 1967