Indeed, the Unseen is known only to Allah, Exalted and Glorified be He. As for fixing a specific day for the Day of Judgment or for saying that certain events well take place in a certain day, all such things are related to the Unseen, something not revealed to anyone; Allah is the Knower of the Unseen; He is All-Knowing!
All what Muslims should do as for the Day of Judgment is to prepare themselves for such a great day by committing themselves to Allah’s teachings.
Concerning the Unseen, Sheikh `Atiyyah Saqr, former head of Al-Azhar Fatwa Committee, says: It is a main principle of `Aqeedah (Islamic Monotheism) to believe in the Unseen. Allah has praised the Believers saying: (…Who believe in the unseen, and establish worship, and spend of that We have bestowed upon them.) (Al-Baqarah 2: 3). There are many Qur’anic verses that deal with the Unseen. For example, Allah, Exalted and Glorified be He, says: (And with Him are the keys of the invisible. None but He knoweth them. And He knoweth what is in the land and the sea. Not a leaf falleth but He knoweth it, not a grain amid the darkness of the earth, naught of wet or dry but (it is noted) in a clear record.) (Al-An`aam 6: 59)
Besides, according to an authentic Hadith narrated by Al-Bukhari, the Unseen includes five things; these are tackled in Allah’s saying: (Lo! Allah! With Him is knowledge of the Hour. He sendeth down the rain, and knoweth that which is in the wombs. No soul knoweth what it will earn tomorrow, and no soul knoweth in what land it will die. Lo! Allah is Knower, Aware.) (Luqman 31: 34)
Allah says also about the Unseen: ((He is) the knower of the Unseen, and He revealeth unto none His secret. Save unto every messenger whom He hath chosen, and then He maketh a guard to go before him and a guard behind him.) (Al-Jinn 72: 26-27)
Regarding the Hadith predicting that people will hear a very deafening and unbearable sound in a month of Ramadan and will be followed by a state of anarchy in the month of Shawal, it is not an authentic Hadith and can not be regarded as true in any way.
According to the book “Al-La’al’ Al-Masnou`ha Fil Ahadith Al-Maudu`ah” (fabricated Hadiths) by As-Suyuti, N’aim Ibn Hamad narrated that Abu Hurairah quoted the Prophet (peace and blessings be upon him) as saying: “An unbearable loud cry will be heard in Ramadan, followed by the upsurge of a gang in Shawwal; a state of anarchy will prevail in Dhul Al-Qidah and during the season of Pilgrimage (Dhul-Hijja) pilgrims will be victims of robbery; then Muharram will witness the acts of trespass against dignity and honor, and deafening cry and sound will echo in Safar. Then in the two Rab’is tribes will enter into many frictions and disputes, and many wonders will take place between (the months) of Jumadah (and Rajab): a camel better than Daskarah (a building in the form of a palace) will carry hundred thousand people.
about this Hadith, the author of “Kanz Al’Umal” said that it was narrated by Ibn Hamad in “Al-Fitan” (Temptations) on the authority of Abu Hurairah; and Al-Hakim condemened it as strange Hadith; while Ad-Dhaby considered it an invented Hadith.
The same Hadith was also reported in the book “Al- Mustadrak” by Al-Hakim, also on the authority of Abu Hurairah who quoted the Prophet (peace and blessings be upon him) as saying: “A very deafening and frightening sound will be heard in Ramadan, awakening him who’s asleep and terrifying him who’s awake…etc.” (to the rest of Hadith).
The great scholars Al-Bukhari and Muslim (may Allah be pleased with them) doubted the credibility of all narrators of this Hadith except Muslimah ibn Ali Al- Husnai; in fact, Muslimah himself is not considered a qualified narrator of Hadiths. So, it is a strange Hadith.
According to another version of the Hadith, the Prophet (peace and blessings be upon him) is quoted as saying, “An unbearable loud cry will be heard in Ramadan, followed by the upsurge of a gang in Shawwal; a state of anarchy will prevail in Dhul Al-Qidah and blood will be shed in Dhu Al-Hijja, and Al-Muharam; what a Muharam! He, peace and blessing be upon him, repeated this statement thrice. Then he proceeded, “What a wonder! What a wonder! During it, people will be killed haphazardly.” We asked, “What about that frightening sound, Allah’s Messenger?” He (peace and blessings be upon him), said: “it will occur due to the fall of a very heavy object in the fifteenth night of Ramadan. In the night of Friday, it will be so loud to the extent of awakening those who are asleep, and terrifying those who are awake, drawing screened women to outdoors. It will occur during a night of Friday, in the first night of the second half of Ramadan, in a year of freezing temperature and full of earthquakes. So if a night of such description occurs, perform the Dawn Prayer, and then go to your home, close your doors, cover your bodies, and your ears with hands. If still you hear the sound, prostrate yourselves before Allah and say:” Glory be to Allah, the Holy. Glory be to Allah, the Holy. Glory be to Allah, the Holy.” He who does do so will be saved; and he fails to do so will be destroyed.
To sum it up, according to the previous narrations, it is obvious that this Hadith is very strange, and many scholars regarded it as a fabricated Hadith.