The last time all living humans were on earth at the same time was November 2nd, 2000. Ever since then, the International Space Station has been constantly manned.
I was also interested to learn that the space shuttle uses Coordinated Universal Time (UTC) and the windows are covered at night hours to give the impression of darkness because the station experiences 16 sunrises and sunsets per day.
MAKING SPACE…FOR BASIC RESEARCH!