John Lennon and Yoko Ono spent their week-long honeymoon in bed in room 902 of the Amsterdam Hilton, the first of their "bed-in" protests against the Vietnam war, now a days having a 'John and Yoko' day is just a brilliant excuse to spend the day in bed with someone, all under the guise of a socially conscious protest!
Woman: I won't be able to make it into work today....
Boss: Why not??
Woman: My boyfriend and I are having a John and Yoko day, it is very important to the future of world peace!