Samuel the Lamanite's Prophecy of the Signs of Christ's Birth

Five years prior to the birth of Jesus Christ, the prophet Samuel the Lamanite appeared in a city and prophesied that in five years, the Son of God would be born. He specified that there would be a sign: the night before his birth, there would be no darkness, and it would appear as if it were day for two days and a night. He also prophesied the appearance of a new star. Years later, an old man and a younger companion witnessed these signs as the sun set but the light of day remained, confirming the fulfillment of the prophecy.

Fuller account of this event (as retold in 3 Nephi 1:15-21, The Book of Mormon):

And it came to pass that the words which came unto Nephi were fulfilled, according as they had been spoken; and behold, at the going down of the sun the people were astonished insomuch that they fell to the earth; for they knew that the great Creator had borne testimony concerning his birth in the land; and they knew that the sign which had been given concerning the birth of Christ was at hand; and they began to fear because of their iniquity and their unbelief. And it came to pass that there was no darkness in all that night, but it was as light as though it was mid-day. And it came to pass that the sun did rise in the morning again, according to its proper order; and they knew that it was the day that the Lord should be born, because of the sign which had been given. And it had come to pass, yea, all things, every whit, according to the words of the prophets. And it came to pass that there was a new star arose, according to the word.