June 21 is the 172nd day of the year (173rd in leap years) in the Gregorian Calendar, with 193 days remaining. June 21 is the summer solstice in the northern hemisphere, so today is the day of the year with the longest hours of daylight in the northern hemisphere, and the shortest in the southern hemisphere.
- 1905 -- Jean-Paul Sartre (philosopher and playwright)
- 1973 -- Juliette Lewis (actress)
- 1982 -- Prince William of Wales (son to Prince Charles and Princess Diana)