The digital sign outside the Great Bend Convention Center features among its rotating images a lit and flaming barbecue grill. Across it are the words “Happy Labor Day.”True, Labor Day has become the traditional end of summer, the closing parenthesis around a season that opened with Memorial Day. Sadly, like many of our holidays, this one has become a symbol of picnics and last trips to the lake.It means so much more.According to the United States Labor Department, Labor Day, the first Monday in September, is a creation of the labor movement and is dedicated to the social and economic achievements of American workers.