What are the three signs that, when they appear, repentance and embracing Islam will no longer be accepted?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu 'alyhi wa sallam, is His slave and Messenger. 

In a Hadeeth (narration) on the authority of Abu Hurayrah the Messenger of Allaah, sallallaahu ‘alayhi wa sallam, said that repentance and embracing Islam would not be accepted by Allaah The Almighty when three things take place: the sun rising from the West, the emergence of the Antichrist and the Beast . [Muslim]

Also, if a person repents when his soul reaches the throat at the time of death, Allaah The Almighty will not accept his repentance. The Prophet, sallallaahu ‘alayhi wa sallam, said that Allaah The Almighty accepts repentance at all times, except when the soul reaches the throat at the time of death. [Ahmad and others, Al-Arnaa’oot and Al-Albaani declared this Hadeeth as (Hasan)]

Allaah Knows best.