The number of lost souls of the 1/3 of fallen angels from Heaven that is completely replenished by saved souls of Catholics on earth, then the Last Judgment occurs.
Yes, God is patient, but the timing of the Apocalypse and, subsequently, Our Lord rendering the Last Judgment has more to do with accumulating the exact number of saved souls of His earthly children to replenish Heaven of the souls of fallen angels that were cast down with Lucifer to hell.
True Divine Mercy would render a global chastisement to purge God's enemies, even if His children were to suffer, too, thus effecting a quicker amount of saved souls in this calamitous wake, which would then bring about a quicker return of Jesus Christ and His rendering the Last Judgment, but due to our sins and lukewarmness, we're being punished with a continual oppression of the Church that won't get lifted and an increasing lawlessness of God's enemies, thus, sowing more sin and hindering souls to Heaven. The world is in a sludge that keeps dragging much slower to Christ's glorious return. The fewer the number of Catholics are in the world who become saved, the longer the duration before Our Savior returns to judge the living and the dead, and casts Satan and his demons into hell forever. It seems that infanticide slows Christ's glorious return, too, because souls are robbed of the opportunity to be Baptized into Christ and enter the Bosom of the Catholic Church, therefore, they can't enter Heaven.
When His return happens, only the Father in Heaven knows.