"The great fierce battle, the conquest of Constantinople and the emergence of Dajjal, will all happen within seven months."
Sunan Ibn Majah Book 36, Hadith 168
← Previous Hadith "You will fight the Arabian Peninsula and victory will be granted by Allah. Then you will fight the Romans and victory will be granted (by Allah). Then you will fight Dajjal and victory will be granted (by Allah)." Jabir said: "Dajjal will not appear until you have fought the Romans."

Sunan Ibn Majah Book 36, Hadith 167 Next Hadith → "Between the fierce battle and the conquest of Al-Madinah will be six years, and the appearance of Dajjal will come in the seventh.'"

Sunan Ibn Majah Book 36, Hadith 169