Is the Day of Reckoning one day?
Question

Is the Day of Reckoning one day?.
Praise be to Allah.Shaykh Muhammad ibn ‘Uthaymeen (may Allah have mercy on him) said:  
The Day of Reckoning is one day, but it is a day whose length is equal to fifty thousand years, as Allah says (interpretation of the meaning): 
“A questioner asked concerning a torment about to befall
Upon the disbelievers, which none can avert,
From Allah, the Lord of the ways of ascent.
The angels and the Rooh [Jibreel (Gabriel)] ascend to Him in a Day the measure whereof is fifty thousand years”
[al-Ma’aarij 70:1-4]
i.e., this torment will befall the disbelievers on a day the length of which is equal to fifty thousand years. 
In Saheeh Muslim it is narrated from the hadeeth of Abu Hurayrah (may Allah be pleased with him) that the Prophet (peace and blessings of Allah be upon him) said: “There is no owner of gold or silver who does not pay what is due on it (i.e., zakaah) but when the Day of Resurrection comes, plates of fire will be prepared for him and with them will be branded his forehead, his flanks and his back, and every time they cool down they will be reheated, on a Day the length of which is equal to fifty thousand years, until judgement is passed among the people.” 
This long Day is the day that will be hard for the kaafirs as Allah says (interpretation of the meaning): 
“and it will be a hard Day for the disbelievers”
[al-Furqaan 25:26] 
“Truly, that Day will be a Hard Day —
Far from easy for the disbelievers” [al-Muddaththir 74:9-10]
What may be understood from these two verses is that it will be easy for the believer, and that is indeed the case. For this long Day with its horrors and serious matters will be made easy by Allah for the believer, but it will be hard for the kaafir.  I ask Allah to make me and my Muslim brothers among those for whom Allah will make the Day of Resurrection easy. 
But thinking too deeply about such matters of the unseen comes under the heading of extremism concerning which the Prophet (peace and blessings of Allah be upon him) said: “Those who go to extremes are doomed, those who go to extremes are doomed, those who go to extremes are doomed .” 
Our duty with regard to the matters of the unseen is to submit and to accept them according to their apparent meaning, without discussing them in depth or trying to compare them to worldly things. For the matters of the Hereafter are not like the matters of this world; even if the meanings may have something in common, there is still a great difference between them. I will give the example of what Allah has told us about there being palm-trees, pomegranates, fruits, the flesh of birds, honey, water, milk, wine etc in Paradise, but He also tells us (interpretation of the meaning): 
“No person knows what is kept hidden for them of joy as a reward for what they used to do” [al-Sajdah 32:17]
And Allah says in a hadeeth qudsi: “I have prepared for My righteous slaves that which no eye has seen, no ear has heard nor has it entered the heart of man.” 
There are things in this world that bear the same names as these blessings of Paradise mentioned here but the fact that they have a name in common does not mean that the wine of Paradise is like the wine of this world, or that the fruits of Paradise are like the fruits of this world, and so on. 
Although they may share a name and a common meaning, all the things of the unseen that share a meaning with things that are seen in this world are not like them in reality, so we should pay attention to this principle and accept the matters of the unseen according to the apparent meanings, and not try to do any more than that.  
Hence when Imam Maalik (may Allah have mercy on him) was asked about the words of Allah (interpretation of the meaning): 
“The Most Gracious (Allah) rose over (Istawa) the (Mighty) Throne (in a manner that suits His Majesty)”
[Ta-Ha 20:5] –
How did He rise over it? He lowered his head and started to sweat, because of the seriousness of this question. Then he raised his head and spoke his famous words that became the standard comment regarding all the attributes that Allah has ascribed to Himself: “(The concept of) rising is not unknown, but how it happened (in the case of Allah) cannot be comprehended. Believing in it is obligatory and asking about it is bid’ah (an innovation).” 
Probing deeply into such matters is bid’ah because the Sahaabah (may Allah be pleased with them) who were more keen than us to seek knowledge and goodness did not ask the Prophet (peace and blessings of Allah be upon him) such questions, and they are sufficient as an example. What I have said now about the Last Day may also be applied to the attributes of Allah which He has ascribed to Himself of knowledge, power, hearing, seeing, speaking etc. The way in which these words apply to Allah is nothing like the way in which the same words apply to man. Each attribute suits the one to whom it is ascribed. Just as there is none like unto Allah in His Essence, there is none like unto Him in His attributes. 
In conclusion: the Last Day is one Day, and it will be hard for the kaafirs and easy for the believers. What has been narrated about the various kinds of reward and punishment is a matter which cannot be fully understood in this world, even though the basic meanings may be known to us in this world.