When will this last day come, we are not told about that hour. ALLAH swt says in Holy Quran:
An-Nazi'aat (79):42-46
"They ask you (O Muhammad sal-Allaahu 'alayhe wa sallam) about the Hour, - when will be its appointed time? You have no knowledge to say anything about it, To your Lord belongs (the knowledge of) the term thereof? You (O Muhammad sal-Allaahu 'alayhe wa sallam) are only a warner for those who fear it, The Day they see it, (it will be) as if they had not tarried (in this world) except an afternoon or a morning."
And
Al-A'raaf (7):187
"They ask you about the Hour (Day of Resurrection): 'When will be its appointed time?' Say: 'The knowledge thereof is with my Lord (Alone). None can reveal its time but He. Heavy is its burden through the heavens and the earth. It shall not come upon you except all of a sudden.' They ask you as if you have a good knowledge of it. Say: 'The knowledge thereof is with Allaah (Alone) but most of mankind know not.''
The knowledge of the final moment is known none other than ALLAH swt. But all prophets came and warned their nations about the last day. The last hour will come all of a sudden without any warning and everything will be destroyed. Muhammad s.a.w.w has told us some signs of the qayamah that are divided into two categories, the major signs and the minor signs. Even Prophet Muhammad s.a.w.w did not know the exact time of the Day of Judgment but He knew that that time is near as mentioned in Quran.
Al- Qamar (54):1
"The Hour has drawn near, and the moon has been cleft asunder."
The Prophet (sal-Allaahu 'alayhe wa sallam) said, whilst pointing with his index and middle fingers, "The time of my advent and the Hour are like these two fingers."
[Bukhaaree, Kitaab at-Tafsir, commentary on Surat an-Nazi'aat, 6/206.]
In another report He said, "The Hour almost came before me."
The verse and the Saying of Muhammad s.a.w.w clearly indicate that the last hour is very near to us. Then there are some ahadith that tell us the signs of qayamah, means if those signs appear we should prepare because qayamah is very near.
Below are given two ahadith that indicate the signs:
Anas ibn Malik said, "I shall tell you a Hadeeth which I heard from the Messenger of Allaah, and which no-one will tell you after me. I heard him say, 'Among the signs of the Hour will be the disappearance of knowledge and the appearance of ignorance. Adultery will be prevalent and the drinking of wine will be common. The number of men will decrease and the number of women will increase until there will be fifty women to be looked after by one man.'"
[This Hadeeth was reported in the two Saheehs from the Hadeeth of 'Abd Rabbihi. A similar Hadeeth was narated by al-Bukhaaree in Kitaab al-'Ilm, 1/30,31; and by Muslim.]
In another hadith it is mentioned with a slight difference:
'Abd Allaah said, "The Prophet (sal-Allaahu 'alayhe wa sallam) said, 'Just before the Hour, there will be days in which knowledge will disappear and ignorance will appear, and there will be much killing.'" [Bukhaaree, Kitaab al-Fitan, 9/61; Msulim, Kitaab al-'Ilm, 8/58.]
In another place MUHAMMAD s.a.w.w. said;
'Alee ibn Abee Taalib said,
"The Prophet (sal-Allaahu 'alayhe wa sallam) said: 'If my Ummah bears fifteen traits, tribulation will befall it.' Someone asked, 'What are they, O Messenger of Allaah?' He said, 'When any gain is shared out only among the rich, with no benefit to the poor; when a trust becomes a means of making a profit; when paying Zakaat becomes a burden; when a man obeys his wife and disobeys his mother; and treats his friend kindly whilst shunning his father; when voices are raised in the mosques; when the leader of a people is the worst of them; when people treat a man with respect because they fear some evil he may do; when much wine is drunk; when men wear silk; when female singers and musical instruments become popular; when the last ones of this Ummah curse the first ones - then let them expect a red wind, or the earth to swallow them, or to be transformed into animals.'"
[Tirmidhee, Abwaab al-Fitan (Hadeeth 308), 6/4620-458, Da`eef, Da`eef al-Jami as-Sagheer: 608.]
How many of the above mentioned things in hadith are nto present today? Wine is drunk even in muslim societies as a status symbol. Singing and songs are culture. Rich and poor have gap that cannot be parted. Men wear silk that was meant to be worn only by women. The leaders of the muslim states are worst. People fight in mosques and they plan and plot against other sects in their mosques. Today we see some people cursing the sahabah openly. So these are the signs already happened.
Major signs include the arrival of dajjal, then coming of ESA a.s, the arrival of gog majoj, the smoke.
May ALLAH protect us from seeing and bearing those times. Amin.