Why is the LAST Sunday?
from Wikipedia, Great Disappointment and Adventist
In August 1844 at a camp-meeting in Exeter, New Hampshire, Samuel S. Snow presented a message that became known as the “seventh-month” message or the “true midnight cry.” In a discussion based on scriptural typology, Snow presented his conclusion (still based on the 2300 day prophecy in Daniel 8:14), that Christ would return on, “the tenth day of the seventh month of the present year, 1844.”[15] Again using the calendar of the Karaite Jews, this date was determined to be October 22, 1844.
The sun rose on the morning of October 23 like any other day, and October 22 became the Millerites‘ Great Disappointment. Hiram Edson recorded that “Our fondest hopes and expectations were blasted, and such a spirit of weeping came over us as I never experienced before… We wept, and wept, till the day dawn.”[16]