One of the least familiar of all Marian apparitions to western ears (at least in my neck of the woods) is Our Lady of the Pillar in Zaragoza, Spain. It really shouldn't be! It was the very first Apparition of Our Lady to have occurred and while she was still alive. Tradition holds that St. James was being stonewalled by pagans in Iberia and nearly at his wit's end he called out to God. It was then that Our Lady bilocated and appeared to him on top of a pillar. She promised to make the faith of those people as strong as the column she was standing on and told him to build a chapel at the site. She left behind a fully carved wooden statue of herself with the Child Jesus on top of a beautiful jade pillar (which no one to this day has determined where it came from).
 
The feast day commemorating this event is October 12, as it happened on that day in the year 40. Columbus himself was a major devotee of this particular apparition, as well as the one in Guadalupe, Spain. In fact, he promised his men that if they hadn't found land by the 12th of October, they would turn around and go back home. There is some dispute over when exactly Columbus was born, but the range they give him means he could have made the discovery in his 40th year. On his second voyage, one of the first islands he came to he named after Our Lady of Guadalupe: Guadeloupe. But more on that later as it connects the two Guadalupes in another amazing way.

Marian Feasts on October 12:
Our Lady of the Pillar, Spain.
Our Lady of Aparecida, Brazil.
Our Lady of Zapopan, Mexico.

Canonical Coronations on October 12:
The tilma in Mexico City, 1895.
The original statue of Our Lady of Guadalupe in Extramadura, 1928.
Madonna di Sant'Alessio in Rome, 1645
Our Lady of the Cape in Quebec, 1904.
Nuestra Señora del Carmen de San Fernando in Spain, 1952.
Nuestra Señora del Pilar de Zamboanga in the Philippines, 1960.

Yesterday 1585 years ago was opening of the Council of Ephesus. This was the copundil that declared Mary is the Mother of God.

Hey Poche, thanks for the reply but as far as I can tell, the council took place in July that year. It was finalized in October so if it didn't start then, maybe something else did toward the end. The closest thing I found was on October 13, 787 during the Second Council of Nicea when the official declaration against Iconoclasm was made. Good thought though, I'm always on the lookout for more "coincidences!"