Apocalyptic expectation has repeatedly generated specific predicted dates, and the pattern of failure and response is itself a recognised phenomenon.
William Miller, an American Baptist preacher, calculated from Daniel that Christ would return between 1843 and 1844; when the recalculated date of October 22, 1844 passed without event, the episode became known among his followers as the Great Disappointment. Rather than dissolving, the movement fragmented and produced continuing traditions, most durably the Seventh-day Adventist Church, which reinterpreted the date as marking a heavenly rather than earthly event. The sociological study of this and comparable episodes, notably Leon Festinger's When Prophecy Fails (1956), examined a UFO-belief group and proposed that failed prediction can intensify commitment through cognitive dissonance and increased proselytising rather than simply ending the movement; later scholarship has qualified how generally that pattern holds.
Jehovah's Witnesses have set and revised several dates across the twentieth century, and popular apprehension around the year 2000, the so-called Y2K phenomenon, blended secular technological anxiety with religious expectation in ways sociologists of religion have studied as a modern hybrid.
The word has also migrated well outside religious use. "Apocalyptic" now describes secular fiction and film about civilizational collapse, and "apocalyptic rhetoric" names a recognised mode of political speech that frames a conflict in absolute, world-ending terms with no room for compromise, a usage scholars of rhetoric trace directly to the genre's structure of crisis followed by decisive, externally supplied resolution, even where no religious content survives at all.