This isn't just another rehashing of the generally unremarkable things that have happened within the last 20 years, this actually goes back about 2500 years.

413 BC A lunar eclipse causes panic among the sailors of the Athens fleet, affecting the outcome of a battle in the Peloponnesian War. The Athenians were ready to move their forces from Syracuse when the Moon was eclipsed. The soldiers and sailors are frightened by this celestial omen and are reluctant to leave. The fleet’s commander, Nicias, consults soothsayers and postpones the fleet’s departure for twenty-seven days. The delay gives an advantage to their enemies, the Syracusans, who go on to defeat the entire Athenian fleet and army, killing Nicias in the process.

You gotta read on for more great info, including the connection between the adult beverage Guinness, and the yearly almanac bearing the same name. The Great Geek Manual » This Day in Geek History: August 27.