Dedication of the Basilica of Saint Mary Major

The Dedication of the Basilica of St Mary Major is a feast day in the General Roman Calendar of the Catholic Church, optionally celebrated annually on 5 August with the rank of memorial.

In earlier editions of the General Roman Calendar, down to that of 1960, it is called the Dedication of the Basilica of St Mary of the Snows, a reference to the legendary story about the foundation of the basilica. For the same reason the feast is also known popularly as Our Lady of the Snows. The reference to the legend was removed in the 1969 revision of the General Roman Calendar.

Source: Wikipedia