John Day received a B.S. degree in business administration from Linfield College in McMinnville, Oregon in 1968. He spent two years building and sailing a wooden sailboat from Oregon to California. He returned to school and received a MBA degree from National University. After graduating, he worked as a corporate accountant. In 1982, he opened his own accounting practice. He began to give seminars to his clients on how to apply the basic functions of accounting to their businesses. In 2005, he published The Heart of Accounting, a textbook covering the essentials of accounting.