Hiram Edson (1806–1882) was a pioneer of the Seventh-day Adventist Church, known for introducing the sanctuary doctrine (investigative judgment) to the church. Hiram Edson was a Millerite adventist, and became a Sabbath-keeping Adventist. Like all Millerites, Edson expected that the Second Coming of Jesus Christ would occur on October 22, 1844. This belief was based on an interpretation of the 2300 day prophecy which predicted that "the sanctuary would be cleansed" which Millerites took to mean that Christ would return on that day.