Miller believed that the cleansing of the sanctuary represented the Earth's destruction by fire at Christ's Second Coming. Using the year-day method of prophetic interpretation, Miller became convinced that the 2,300-day period started in 457 BC with the decree to rebuild Jerusalem by Artaxerxes I of Persia. Simple calculation then indicated that this period would end about 1843. In September 1822, Miller formally stated his conclusions in a twenty-point document, including article 15, "I believe that the second coming of Jesus Christ is near, even at the door, even within twenty-one years,—on or before 1843." This document remained private for many years.