May 6

Lesson in Pushing the Limits, Part I
Englishman Roger Bannister ran the first sub-four-minute mile on this day in 1954, a feat thought to be impossible. The current record, set in 1999 by Morocco's Hicham El Guerrouj, is 3:43:13.

May 9

Sparking A Million Sexism Debates
On this day in 1958, Ruth Handler, a toymaker in Los Angeles, came up with the product name Barbie. Interest in the doll was lukewarm at the New York Toy Fair the following year, but Handler's company, Mattel, sold more than 351,000 dolls in 1959 and went public in 1960.

May 12

In Honor of Limerick Day
You find your verse funny, we know,
But you're filling employees with woe.
Though it's Limerick Day,
Keep your mouth shut, hombre.
Don't make them call AFL-CIO.

May 17

Money on the Mind
The New York Stock Exchange was founded on this day in 1792. "Meeting under a buttonwood tree, today the location of 68 Wall Street, the traders agreed to establish a formal exchange for the buying and selling of shares and loans," writes Charles R. Geisst in Wall Street: A History ($20, Oxford University Press). The early rule governing trading hours remains in effect, but payments no longer have to be made in specie.

May 29

Lesson in Pushing the Limits, Part II
One year before Bannister set his record, Edmund Hillary and Tenzing Norgay became the first people to reach the summit of Mount Everest, an achievement that business executives have been using as a metaphor ever since.