It is lecture in Urdu by Allama Ishfaq Ahmad of Lahore(Pakistan) about conquest of makkah by Hazrat Muhammad (s.a.w.) in ramadan 8 hijrah , wikipedia says that " Mecca was conquered by the Muslims on 11 December 629 CE (Julian), 18 Ramadan, 8 AH in the ancient (intercalated) Arabic calendar. It was not until the Farewell Pilgrimage in 632 CE that the practice of intercalation fell into disuse. Muhammad started the journey on 6 Ramadan and entered Mecca on 18 Ramadan"