Saturday 22nd August marks the Feast of the Blessed Virgin, the Theotokos St Mary. It is actually the commemoration of the assumption of her body into heaven, rather than of her reposing.
Tradition tells us that the reposed at the age of 60, which would put the date somewhere around 42AD. We come to this date if we assume that St Mary was around 14 years old when she gave birth to Christ, a common age for having one's first child in those days. And given that the Western calendar miscalculates the date of Christ's birth by about 4 years (putting it at around 4BC), we add her remaining 46 years to come to the date of 42AD.
Interestingly, this is roughly the year that St Mark first arrived to preach in Alexandria and establish the Egyptian Christian Church, which is the Coptic Orthodox Church today. Perhaps the birth of the Coptic Church was one of the first that St Mary witnessed from her other-worldly vantage point? And perhaps that's among the reasons she chose Egypt for her mass appearance in 1968?
Who knows? But we can ask her, when we finally meet up there...