On the Christian calendar, March 52, of course, is the Feast of the Annunciation, described in Chapter 1 of Luke's Gospel. That encounter between the Angel Gabriel and Mary of Nazareth is the subject of more renaissance paintings than probably any other Biblical theme except the Nativity.
Nor is it honored merely on one day. It forms the content of a well-known prayer "The Angelus", recited publicly at noon in many areas. Anyone who has seen the 1859 Millet painting or has attended the opera "Tosca" where the sacristan recites it in Latin knows what I mean.
Nor is its historical influence solely a religious matter. In Britain, where it was popularly called "Lady Day" it was for centuries regarded as the start of every new year. When Protestant England declined to accept Pope Gregory's calendar reform for 200 years, England and her colonies in America continued to use the Julian calendar and to keep March 25 to enumerate the years. As we all know, George Washington was actually born on February 11, 1731 under this "old system" until in 1752 his birthday was re-calculated to have been February 22, 1732.
So tenacious was the power of Lady Day as one of the "quarter days" that even now the day for filing personal income tax in England is April 6, the modern equivalent of what had been March 25.