Professor Day is known for his research on aligning organizations with their markets competitive strategies in global markets, strategy development, and managing innovation processes. He consults extensively with major companies worldwide, including IBM, DuPont and Medtronic, assisting them with marketing management, strategic planning and competitive strategies.

The author of the seminal Market Driven Strategy, Professor Day has published more prize-winning research articles in the Journal of Marketing than any other marketing professional. His recent research offers new insight into how organizations sense and act on weak signals from their periphery. Professor Day's other current research focuses on how innovative organizations choose their growth directions, building market-driven organizations and competing for customer relationships. Professor Day's book, Wharton on Managing Emerging Technologies is described as one of the first broad, research-based views of this new competitive terrain, drawing together the perspectives of experts in strategy, marketing, public policy, management, alliances and organizational design.

Professor Day's research has been published in top-tier journals including the Strategic Management Journal, Journal of Marketing, Harvard Business Review and Journal of Marketing Research. He also serves or has served as Section Editor on the Editorial Boards for the Journal of Marketing, Strategic Management Journal, and Journal of Marketing Research among other leading journals. A former Executive Director of the Marketing Science Institute, Professor Day has won many of the marketing field's highest honors, including the Paul D. Converse and Charles Coolidge Parlin Award for outstanding contributions to marketing and marketing education, the AMA/Irwin Distinguished Educator Award and the Academy of Marketing Science's Outstanding Marketing Educator Award.

Professor Day's teaching interests include courses in Strategic Marketing, Essentials of Marketing, and Competitive Strategies. He received his PhD from Columbia University, his MBA from the University of Western Ontario, Canada, and his B.A.Sc from the University of British Columbia, Canada.