John Lennon celebrated his 27th birthday on this day.
Since 27 September 1967 he had been receiving daily postcards from the artists Yoko Ono, after subscribing to her postal art event 13 Days Do It Yourself Dance Festival. Each morning participants received a short instructional message.
This day's message, the final in the series, said: "Colour yourself. Wait for the spring to come. Let us know when it comes."