It already has a far-flung network of sorting centers and letter carriers that allows it to deliver physical documents to every U.S. address six days every week.

CNN: Save the Postal Service from collapse

The radiation exposure from a Mars journey is similar to getting a full-body CT scan every five or six days, said lead researcher Cary Zeitlin of the Southwest Research Institute in Boulder, Colo.

NPR: Astronauts Face Radiation Threat On Long Mars Trip

The company typically runs sales for brands for three to five days every four to six weeks.

FORBES: Connect

Do you think it is a coincidence that every secondary offering trades down five or six days before the offering.

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"I probably play every day, two to three hours, six days a week, " he says.

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And yet it is obliged (as FedEx and UPS are not) to visit every mailbox, no matter how remote, six days a week.

ECONOMIST: The Post Office

The Act removed a statute of limitations on discriminatory pay practices, setting the time limit to six months for every paycheck where the employee was discriminated against (and not 180 days from the date of the first paycheck).

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For the next 17 days, more than six million normally prim and sober citizens from every country in the world will descend upon the Theresienwiese festival grounds (Wiesn, for short) to guzzle towering mugs of beer and engage in good cheer and outright debauchery.

BBC: Oktoberfest turns 200

Days later FORBES got a six-page letter from Bogle, critiquing every word in the story and every point of logic.

FORBES: Sidelines

Dr. Bollen and his colleagues, for example, found that the millions of Twitter messages sent via mobile phones and computers every day captured swings in national mood that presaged changes in the Dow Jones index up to six days in advance with 87.6% accuracy.

WSJ: The Really Smart Phone