Times When Du`a Is Accepted
Question

What are the times, places and situations where du`a is answered? And what is meant by the words of the Prophet (peace and blessings of Allah be upon him) “Dubur al-salawat al-maktubah (following the prescribed prayers)”? Is the prayer of a father for his child answered, or is it a prayer against him that is answered? I hope you can explain all these matters.
Praise be to Allah.There are many times and places where du`a is answered. There follows a summary thereof: 

Laylat al-Qadar . ‘Aishah asked the Prophet (peace and blessings of Allah be upon him): “If I know what night is Laylat al-Qadar, what should I say during it?” He said: “Say: Allahumma innaka 'afuwwun tuhibb ul-‘afwa fa’fu ‘anni (O Allah, You are forgiving and love forgiveness, so forgive me).” 
 Du`a in the depths of the night, the time before dawn, the time when Allah descends to bestow His bounty upon His slaves, to meet their needs and to relieve their distress, when He says: “Who will call upon Me, that I may answer Him? Who will ask of Me, that I may give him? Who will seek My forgiveness, that I may forgive him?” (Narrated by al-Bukhari, 1145) 
Following the prescribed prayers . According to the hadith of Abu Umamah, it was said: “O Messenger of Allah, which du`a is heard?” He said: “In the last third of the night, and following the prescribed prayers.” Narrated by al-Tirmidhi, 3499; classed as hasan by al-Albani in Sahih al-Tirmidhi. 

There was some difference of scholarly opinion concerning the phrase dubur al-salawat al-maktubah (“following the prescribed prayers”) – does it mean before the salam or afterwards? 
Shaykh al-Islam Ibn Taymiyah and his student Ibn al-Qayyim were of the view that it is before the salam. Ibn Taymiyah said: “The word dubur refers to something that is part of a thing, like dubur al-hayawan (the hindquarters of an animal).” Zad al-Ma'ad, 1.305. Shaykh Ibn ‘Uthaymin said: “What has been narrated of du`a following the prayer is before the salam and what has been narrated of dhikr following the prayer is after the salam, because Allah says (interpretation of the meaning): 
“When you have finished As-Salah (the congregational prayer), remember Allah standing, sitting down, and (lying down) on your sides.” [al-Nisa 4:103]  (See: Kitab al-Du`a by Shaykh Muhammad al-Hamad, p. 54)

Between the adhan and the iqamah. It is narrated in a sahih report that the Prophet (peace and blessings of Allah be upon him) said: “A du`a offered between the adhan and iqamah is not rejected.” (Narrated by Abu Dawud (521) and al-Tirmidhi (212). See also Sahih al-Jami’, 2408) 
When the call for the prescribed prayers is given and when the ranks are drawn up for battle, as it says in the marfu' hadith of Sahl ibn Sa’d: “There are two that will not be rejected, or will rarely be rejected: du`a at the time of the call for prayer and at the time of battle when the fighting begins.” (Narrated by Abu Dawud; it is a sahih report. See Sahih al-Jami’, 3079) 
When rain falls , as it said in the hadith of Sahl ibn Sa’d that is attributed to the Prophet (peace and blessings of Allah be upon him): “There are two which will not be rejected: du`a at the time of the call (to prayer) and when it is raining.” (Narrated by Abu Dawud and classed as sahih by al-Albani in Sahih al-Jami’, (3078). 
At a certain time of the night, as the Prophet (peace and blessings of Allah be upon him) said: “During the night there is a time when the Muslim does not ask for the good of this world and the Hereafter but it will be given to him, and that happens every night.” (Narrated by Muslim, 757)
A certain time on Friday .  The Messenger of Allah (peace and blessings of Allah be upon him) mentioned Friday and said: “During it there is a time when a Muslim slave does not stand and pray and ask Allah for something, but He will give it to him,” and he gestured with his hand to indicate how short that time is. (Narrated by al-Bukhari, 935; Muslim, 852. See also question no. 21748) 
When drinking Zamzam water . Jabir (may Allah be pleased with him) narrated that the Prophet (peace and blessings of Allah be upon him) said: “Zamzam water is for that for which it is drunk.” (Narrated by Ahmad and classed as sahih by al-Albani in Sahih al-Jami’, 5502) 
When prostrating. The Prophet (peace and blessings of Allah be upon him) said: “The closest that a person is to his Lord is when he is prostrating, so say a great deal of du`a then.” (Narrated by Muslim, 482)
When hearing the crowing of a rooster, because of the hadith: “When you hear the crowing of a rooster, ask Allah of His bounty, for he has seen an angel.” (Narrated by al-Bukhari, 2304; Muslim, 2729) 
When saying the du`a, “La ilaha illa anta, subhanaka, inni kuntu min al-zalimin ([none has the right to be worshipped but You (O Allah)], Glorified (and Exalted) be You [above all that (evil) they associate with You]! Truly, I have been of the wrongdoers – cf al-Anbiya 21:87]).” It was narrated in a sahih hadith that the Prophet (peace and blessings of Allah be upon him) said: “The prayer of Dhu’l-Nun (Yunus) which he said when he was in the belly of the whale: ‘La ilaha illa anta, subhanaka, inni kuntu min al-zalimin ([none has the right to be worshipped but You (O Allah)], Glorified (and Exalted) be You [above all that (evil) they associate with You]! Truly, I have been of the wrongdoers.’ No Muslim recites this du`a concerning any matter but Allah will answer him.” Narrated by al-Tirmidhi and classed as sahih in Sahih al-Jami’, 3383.  

In his commentary on the passage (interpretation of the meaning): 
“And (remember) Dhun-Nun (Jonah), when he went off in anger, and imagined that We shall not punish him (i.e. the calamities which had befallen him)! But he cried through the darkness (saying): La ilaha illa Anta [none has the right to be worshipped but You (O Allah)], Glorified (and Exalted) be You [above all that (evil) they associate with You]! Truly, I have been of the wrongdoers.” So We answered his call, and delivered him from the distress. And thus We do deliver the believers (who believe in the Oneness of Allah, abstain from evil and work righteousness).” [al-Anbiya 21:87-88] 
Al-Qurtubi said:  In this verse, Allah stipulates that whoever calls upon Him, He will answer him as He answered and saved Dhu’l-Nun (Yunus). This is what is meant by the words “And thus We do deliver the believers”. (Al-Jami’ li Ahkam il-Quran, 11/334) 

 If a calamity befalls him and he says, Inna Lillahi wa inna ilayhi raji’un, Allahumma ujurni fi musibati w'ukhluf li khayran minha (Truly, to Allah we belong and truly, to Him we shall return; O Allah, reward me in this calamity and compensate me with something better than it). It was narrated by Muslim in his Sahih (918) that Umm Salamah said: I heard the Messenger of Allah (peace and blessings of Allah be upon him) say: “There is no calamity that befalls one of the Muslims and he responds by saying ‘Inna Lillahi wa inna ilayhi raji'un, Allahumma ujurni fi musibati w'ukhluf li khayran minha (Truly, to Allah we belong and truly, to Him we shall return; O Allah, reward me in this calamity and compensate me with something better than it),’ but Allah will compensate him with something better than it.” 
 The prayer of people after the soul of the deceased has been taken. According to the hadith, the Prophet (peace and blessings of Allah be upon him) entered upon Abu Salamah (after he had died) and his eyes were open. He closed them and said: “When the soul is taken, the gaze follows it.” Some of his family got upset and he said: “Do not pray for anything but good for yourselves, for the angels say Amin to whatever you say.” Narrated by Muslim. 2732. 
Du`a for one who is sick. Muslim (919) narrated that Umm Salamah said: The Messenger of Allah (peace and blessings of Allah be upon him) said: “When you visit a sick person, say good things, for the angels say Amin to whatever you say…” When Abu Salamah died, I came to the Messenger of Allah (peace and blessings of Allah be upon him) and said: “Abu Salamah has died.” He said: “Say: O Allah, forgive me and him, and compensate me well.” She said: I said: And Allah compensated me with one who was better for me than him: Muhammad (peace and blessings of Allah be upon him). 
 The prayer of the one who has been wronged. In the hadith it says: “Fear the prayer of the one who has been wronged, for there is no barrier between it and Allah.” Narrated by al-Bukhari, 469; Muslim, 19. And the Prophet (peace and blessings of Allah be upon him) said: “The prayer of the one who has been wronged will be answered, even if he is an evildoer, for his evildoing is only against himself.” Narrated by Ahmad. See Sahih al-Jami’, 3382. 
 The du`a of a father for his child – i.e., for his benefit – and the du`a of a fasting person during the day of his fast, and the prayer of the traveller. It was narrated in a sahih report that our Prophet (peace and blessings of Allah be upon him) said: “There are three prayers that are not rejected: the prayer of a father for his child, the prayer of the fasting person and the prayer of the traveller.” Narrated by al-Bayhaqi; see Sahih al-Jami’, 2032; al-Sahihah, 1797. 
 The prayer of a father against his child – i.e., to harm him. According to a sahih hadith: ‘There are three prayers that will be answered: the prayer of one who has been wronged, the prayer of a traveller, and the prayer of a father against his child.” Narrated by al-Tirmidhi, 1905. See Sahih al-Adab al-Mufrad, 372. 
 The du`a of a righteous person for his parents, as stated in the hadith narrated by Muslim (1631): “When the son of Adam dies, all his good deeds come to an end except three: ongoing charity, a righteous son who will pray for him, or beneficial knowledge.” 
 Du`a after the sun has passed its zenith and before Zhuhr. ‘Abd-Allah ibn al-Saib (may Allah be pleased with him) narrated that the Messenger of Allah (peace and blessings of Allah be upon him) used to pray four rak'ahs after the sun had passed its zenith and before Zhuhr, and he said: “This is a time when the gates of heaven are opened and I want a good deed of mine to ascend during this time.” (Narrated by al-Tirmidhi and its isnad is sahih. See Takhrij al-Mishkaat, 1/337) 
 Du`a when getting up from the night (sleep), and saying the du`a that was narrated for that time. The Prophet (peace and blessings of Allah be upon him) said: “Whoever awakens from the night and says La ilaha ill-Allah wahdahu la sharika lah, lahu al-mulku wa lahu al-hamd, wa huwa 'ala kulli shay-in qadir. Alhamdulillah, wa Subhanallah, wa la ilaha illa Allah wallahu akbar wa la hawla wa la quwwata illa Billah (There is no god but Allah Alone, He has no partners, His is the Sovereignty, to Him belongs praise and He is over all things Capable. Glory be to Allah, there is no (true) God but Allah, and Allah is Most Great and there is no power and no strength except with Allah), then he says: Allahumma ighfir li (O Allah, forgive me), or he makes du`a, his prayer will be answered, and if he does wudu and prays, his prayer will be accepted.” Narrated by al-Bukhari, 1154.

And Allah knows best.