Narrated from Sayyiduna Abdullah bin Amr, may Allah be pleased with them both, he says: Whoever repents one year before his death, his repentance will be accepted; whoever repents one month before his death, his repentance will also be accepted, until he mentioned even one day, one hour, and even a moment (fuwaaq). A man asked: What is your opinion if a person is a polytheist and then becomes a Muslim at that time? He said: I will only relate to you as much as I have heard from the Messenger of Allah, peace and blessings be upon him.
Hadith Referenceالفتح الربانی / كتاب التوبة / 10166
Benefits: … By "fuwaaq" is meant the interval between two milkings, and the time between the milker grasping the udder twice; here, the second meaning is intended, because the mention of an hour has already occurred before this.