This was The Beatles' second day off during their five-day break in the 1965 North America tour. They rented a house owned by Zsa Zsa Gabor at 2850 Benedict Canyon, Beverly Hills, where they were visited by a number of people.
This was the day on which John Lennon and George Harrison had their second LSD experience. Ringo Starr tried the drug for the first time, although Paul McCartney did not partake on this occasion.
Among the visitors on this day were Eleanor Bron, whom had appeared with The Beatles in Help!, Roger McGuinn and David Crosby of The Byrds, and Daily Mirror newspaper journalist Don Short.
Indian music and LSD were key influences in the changes in The Beatles' music between 1965 and 1968. The drug, in particular, played a pivotal role in the group's studio experimentation for Revolver and Sgt Pepper's Lonely Hearts Club Band.
According to George Harrison, he and Lennon had decided that the other Beatles should experience LSD, which they had previously taken in London sometime between March and July 1965.
Although McCartney was wary of the experience, Starr embraced it enthusiastically. Despite the general party atmosphere, police and security were stationed around the house to keep fans away. In addition, not all The Beatles' visitors were aware that the group was on LSD.
Source: Beatles Bible