Is the time of the Divine Descent the last depth of the night (the fifth sixth of the night's sixths), or the last third of the entire night?

Allah Almighty descends to the lowest heaven during the last third of the night, which comprises the fifth and sixth sixths. This descent begins in the fifth sixth and continues until dawn. This time is most propitious for the acceptance of supplications and for forgiveness, as stated in the Hadith (definition) narrated by Abu Hurayrah and others, and in the words of the Prophet, peace and blessings be upon him: "In the last depths of the night, and after the prescribed prayers."