August 15 is Mary's heavenly birthday (Assumption of Mary ~ Mary's assumption of body and soul into Heaven)
The Solemnity of the Assumption on August 15 was celebrated in the eastern Church from the 6th Century. The Catholic Church adopted this date as a Holy Day of Obligation to commemorate the Assumption of the Blessed Virgin Mary, the real physical elevation of her sinless soul and incorrupt body into Heaven.

Desdemona and Emilia are preparing for bed.Desdemona asks Emilia to put out the bridal gown she used on her wedding day, and says that if she dies, she wants to be buried in it.Emilia tells her not to talk about such things.Desdemona recalls how her mother had a servant named Barbara, who fell in love with a man but went mad when he left her(Desdemona: Piangea cantando nell’erma landa / "Singing, she wept on the lonely hearth", also known as the Willow Song).After Emilia leaves, Desdemona prays (Ave Maria 詞同一般聖母頌) and then falls asleep.