Even amid the pressing concerns stemming from a volatile economy that often keep business leaders up a night, Tom Monahan, chief executive of the Corporate Executive Board, decided recently for one day to shut down operations at the 24-story headquarters in Arlington overlooking the Potomac River, leaving only a handful of employees behind.

Foregoing his usual business meetings with investors and customers, Monahan donned a T-shirt, jeans and a cap. He had only one item on his agenda that day: to build an octopus.

The sea creature built with tires was one of 34 projects that he and 800 local Corporate Executive Board employees completed during the company’s first Global Day of Service, during which it partnered with volunteerism nonprofit City Year to refurbish Ferebee-Hope Elementary school in Southeast Washington.

Monahan says the service day, which galvanized 1,700 employees in its 14 offices worldwide, will also help “knit our offices together on a global basis.”

Employees set up health camps in India, took disadvantaged youth to a zoo in Australia and supported a community festival in Singapore while executives e-mailed each other pictures of their events.

Here in the District, a team of employees gave each other high-fives as a thick branch from the tree they were pruning fell to the ground.

Spray painting the school’s name on the wall, an executive in the company’s member sales and services department joked about how he’ll tell his kids what he did at work that day.

The sounds of hammering, sanding and drilling, mixed with pop music coming from a radio, permeated the school’s play yard while a cluster of employees from the creative production services department sat in a pool of crayons, Googling famous quotes on their phones to think of inspirational words to write on a mural made of book pages.

The Corporate Executive Board in 2008 created a Community Partner’s program that selects a handful of nonprofit partners every couple of years to which it will provide funds, service and pro bono consulting. Last year it gave $1 million in funding.

This year, in addition to the $80,000 it gave to City Year, it established partnerships with Streetwise Partners, Ashoka and LUNGevity.

“Community service is one way we try to instill and reinforce that sense of pride for our employees,” said Jerry Sorkin, the company’s executive director of philanthropy and service.