Day & Zimmermann

Day & Zimmermann is a family-owned company with a workforce of over 42,000 specializing in construction & engineering, staffing and defense solutions for leading corporations and governments around the world. Operating from more than 150 worldwide locations with 2.4 Billion USD in revenue, Day & Zimmermann is currently ranked as one of the largest private companies in the U.S. by Forbes. Headquartered in Philadelphia, PA, their first work was to develop "Betterment Reports"​ that helped modernize American factories. Today, they are still in the business of betterment—maintaining the nation's power infrastructure, protecting American freedoms and driving technological advancements around the world.