In his book the great Sunni scholar Suyuti relates trustworthy hadith regarding that the life of the world lasts 7000 years
1. Ibn Asaqir says: Abu Said Ahmed ibn Muhammad Baghdadi (with the full history of its transmission) narrated. He said from Anas ibn Malik (ra) that The Messenger of Allah (saas) said:
Allah will ascribe the equivalent of good deeds of the seven thousand years of the age of this worldto the one who meets the need of any of his brothers in the faith on the path of Allah as if he spends his days in fasting and his nights in worship.
2. Ibn Abiyy says: Abu Ishak narrated from Ibrahim b. Abdullah Nabt (with the full history of that transmission) narrated. He said from Anas ibn Malik (ra) that The Messenger of Allah (saas) said:
The life span of the world is seven days in the afterlife days. Almighty Allah said, “a day with your Lord is equivalent to a thousand years in the way you count”.
3. Ibn Abi ad-Dunya says that: Ali ibn Said narrated from Hamza ibn Hisham and he from Said ibn Jubair that,
The world is one week of the weeks of the Hereafter.
4. Ibn Abi Hatam narrates from Ibn Abbas in the Commentary that:
The world is one week of the weeks of the Hereafter, it is seven thousand years, of which six thousand have already gone by.
He said: The world is seven days. Each day is like a thousand years.And The Messenger of Allah (saas) was sent at the end of that.
6. At-Tabarani in al-Mu'jam al-Kabir says: Ahmad ibn Nadr al-Askari and Jaffar Ibn Muhammad al-Faryabi (with the full history of its transmission) narrated. They said from Daqqaq Ibn Zaid Al-Juhani that,
I had a dream and told it to Messenger of Allah (saas). He spoke the words inside him: O Messenger of Allah, I am with you on a seven-stepped pulpit, and you are on its highest degree.He (saas) said: As for the seven-stepped pulpit, I am on the highest step, the life of the world is seven thousand years.And I shall be in the last thousand.
Allah created the earth and sky in six days. A day with your Lord is equivalent to a thousand years in the way you count. And the life span of the world is six days, and the Day of Reckoning will fall on the seventh. Six days have gone by, and you are in the seventh.
Five thousand six hundred years have passed from this world.
Al-Muttaqi al-Hindi, Al-Burhan fi Alamat al-Mahdi Akhir az-Zaman, p. 88.