Repentance is accepted up until before death

from the Prophet ﷺ "Indeed Allah accepts the repentance of a slave until he gargles (soul reaching the throat at time of death)."  

عَنِ النَّبِيِّ ﷺ قَالَ «إِنَّ اللَّهَ يَقْبَلُ تَوْبَةَ الْعَبْدِ مَا لَمْ يُغَرْغِرْ۔»