This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
When 1843 passed without the return William Miller had calculated from Daniel, his followers did not abandon the expectation, they recalculated. Samuel Snow proposed a sharper date, October 22, 1844, which became the movement's final and most specific prediction. Miller himself was more cautious than his own followers, accepting Snow's new date only in its final weeks, after most of the wider movement had already embraced it.
October 22, 1844 passed the same way 1843 had, without the expected event, in what Millerites themselves came to call the Great Disappointment, a phrase that named the movement's defining crisis in its own words rather than a label applied only afterward by outsiders. The scale of the following that had gathered around the date, built through a decade of preaching and Joshua Himes's publishing effort, made the failure a public and collective crisis rather than one man's private error.
Miller's own response to that second failure is notable set against how the movement around him fractured. He continued to affirm that Christ's return was near without ever setting a further specific date, and he died in 1849 without founding any of the several successor bodies, including the movement that would become Seventh day Adventism, that grew from the Millerite following after his death, leaving the calculation's legacy to be shaped by others rather than by himself.