His Birth:
Imam Muslim was born in 204 AH, as stated in Khalāṣat Tadhīb al-Kamāl by al-Khazrajī, in Tadhīb al-Tahdhīb and its abridgment Taqrīb by the ḥāfiẓ Ibn Ḥajar al-ʿAsqalānī, and likewise in Ibn Kathīr’s al-Bidāyah wa-l-Nihāyah. The latter, after recording his death in 261 AH, wrote: “He was born in the year in which al-Shāfiʿī died—that is, 204 AH—so his age was fifty-seven years; may Allah have mercy on him.”

Ibn Khallikān, in Wafayāt al-Aʿyān, quoting from ʿUlamāʾ al-Amṣār by Abū ʿAbd Allāh al-Ḥākim al-Nīsābūrī, reports that Muslim passed away in Nīshābūr with five days remaining of Rajab al-Fard—the solitary sacred month—in 261 AH, at the age of fifty-five. He then remarks: “That would place his birth in 206 AH.”