How to calculate the precise one third end of the night?

How to calculate the precise one-third end of the night when Allah descends to the earth’s sky?

In the authority of Abu Hurayrah (may Allah be pleased with him), who said that the Messenger of Allah (peace and blessings of Allah be upon him) said: “Our Lord (glorified and exalted be He) descends each night to the earth’s sky when there remains the final third of the night, and He says: ‘Who is saying a prayer to Me that I may answer it? Who is asking something of Me that I may give it to him? Who is asking forgiveness of Me that I may forgive him?'” [Bukhari (also by Muslim, Malik, at-Tirmidhi and Abu Dawud).]
In a version by Muslim, the Hadith ends with the words: “And thus He continues till [the light of] dawn shines.”

Here is how you figure the exact time using an easy example:
You start off by figuring out the number of hours between {Maghrib} and time of {fajr} in your area.

Let’s assume Maghrib is at 6:00 PM


Let’s also assume Fajr is at 6:00 AM.

Between Maghrib and Fajr in this example is 12 hours.

3 (The three portions of the night) divided into 12 hours (total hours between Maghrib and Isha) = you get 4.

a) 6 PM maghrib time plus 4 hours (6 + 4) = 10 PM.
(6 PM to 10 PM) is the 1st 1/3 of the night.

b) 10 PM plus 4 hours (10 + 4) = 2 AM.

(10 PM to 2 AM) is the 2nd 1/3 of the night.

c) 2 AM plus 4 hours (2 + 4) = 6 AM.

(2 AM to 6 AM) is the final 1/3 end of the night.

***Also, note that the middle of the night is not fixed at 12 AM as many assume.
The middle of the night in the above scenario would be to take the 12 hours between Maghrib and Isha and get half of that = 6

6 PM maghrib plus 6 hours = 12 AM is middle of the nights in the scenario but it will vary according to your area.