In 1950, Venerable Pius XII defined the dogma of the Assumption Ex Cathedra. Since that day, the Feast of the Assumption of the Blessed Virgin Mary has been celebrated every 15th of August! This feast is also known as Marymass or Saint Mary’s Day and it is a Holy Day of Obligation (yes, you have to go to Mass). It is the day that we recall Our Lady’s being assumed into Heaven and crowned Queen!

“Nous proclamons, déclarons et définissons que c’est un dogme divinement révélé que Marie, l’Immaculée Mère de Dieu toujours Vierge, à la fin du cours de sa vie terrestre, a été élevée en âme et en corps à la gloire céleste.”  Proclamation dogmatique – 1er novembre de l’Année sainte 1950.

Here is the actual video of Venerable Pius XII: