Not graded
Mishkat al-Masabih 5425
وَعَنْهُ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسلم: «الملحمة الْعُظْمَى وَفتح القسطنطينة وَخُرُوجُ الدَّجَّالِ فِي سَبْعَةِ أَشْهُرٍ» . رَوَاهُ التِّرْمِذِيُّ وَأَبُو دَاوُد
He reported God's messenger as saying, "The greatest war, the conquest of Constantinople, and the coming forth of the dajjal will take place within a period of seven months." Tirmidhi and Abu Dawud transmitted it.
Cited in Mishkat al-Masabih (No. 5425).