MLR Holdings’ Bill Rock joins Day & Zimmermann Board of Advisors 

PHILADELPHIA, PA—December 6, 2022 – Day & Zimmermann (D&Z), the 120-year-old, family-owned provider of construction & engineering, staffing, and defense solutions for leading corporations and governments around the world, announced today that Bill Rock, President and CEO of MLR Holdings, has joined Day & Zimmermann's Board of Advisors. Rock brings to the board extensive media, corporate governance and family business expertise, as well as business intelligence and technology market research experience.

 “I am pleased and honored to have the opportunity to serve on the board,” said Rock. “Day & Zimmermann is a wonderful company with a rich history and an even brighter future. I have great respect for the company, the Yoh family, and the customers they serve.” 

 MLR Holdings owns media and B2B information businesses, including MLR Media. Through digital platforms, live events and print magazines, including Directors & Boards, Private Company Director and Family Business magazines, MLR Media provides public and private company directors, leaders and owners of multi-generational family businesses, and C-suite executives with the knowledge and skills to be successful in their roles. 

Under Rock’s leadership, MLR Holdings owned Uptime Institute, the global leader in data center certifications, until January 2022, when it was acquired by Dominus Capital; and 451 Research, a leading provider of business intelligence and market data for the technology markets, until December 2019, when it was acquired by S&P Global (NYSE: SPGI). Uptime Institute has awarded more than 2,000 certifications, accredited over 5,000 highly specialized technical experts and provided advisory services in over 95 countries.  451 Research is the leading provider of essential business intelligence and market data to leaders of the digital economy via syndicated research and proprietary data, advisory services and live events. 

Prior to joining MLR Holdings, Rock was a management consultant. He received his B.A. from Harvard University, his M.B.A. from the Wharton School of the University of Pennsylvania, and his J.D. from the University of Pennsylvania Law School. Bill is a member of YPO (the world’s largest leadership community of chief executives) and a member of the boards of trustees of TJUH System and Thomas Jefferson University Hospitals. 



When you’ve been around for more than a century, you know a thing or two. At Day & Zimmermann, we take our lifetime of experience and make things better. Our 51,000+ employees help bring big ideas to life every day. We’re pushing the boundaries of innovation in construction & engineering, operations & maintenance, staffing, and security & defense. And that’s not all. Did we mention that we have 150+ worldwide locations with $2.7 billion USD in annual revenue? We put people to work, we protect American freedoms, and we help our customers power and improve the world. We do what we say.® 


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