xlab : mac os x weblog tells us about looking up dates in the Terminal.
Paul Bissex shares a curious feature installed with OS X while writing a script. Open a Terminal and type
cat /usr/share/calendar/* | grep `date “%m/%d”`
Turns out /usr/share/calendar is full of historical date information.
Hmmm, on this day Janis Joplin died of a heroin overdose in 1970 and in 1957 Sputnik 1 was launched.