Note: This article is taken from Society of St. Vincent Ferrer.
(1) Creation - According to very ancient sources, March 25th is the day of creation. Contrary to the false science and errors of evolution, Scripture and Tradition teach that God created instantaneously (simply by speaking) and out of nothing. There are also traditions that relate March 25th was the day on which Adam and Eve were created and therefore also the day on which Adam and Eve committed the Original Sin.
(2) Incarnation - It was on this same calendar day that Jesus Christ assumed our human nature. March 25th is the day of the Mysteries of the Annunciation and Incarnation. On this day, God sent the archangel Gabriel to the Virgin Mary and she gave her fiat. As we well know, Christ was then born nine months later, on Dec 25th.
(3) Crucifixion - We read in the Roman Martyrology that March 25th is also the day on which St. Dismas, the good thief, died. This corroborates the ancient and venerable tradition that Our Lord was crucified on March 25th. In other words, the calendar date of the original Good Friday was March 25th. St. Irenaeus explains that it is eminently fitting that on the same day which the fallen angel seduced the virgin Eve, so on that day the archangel Gabriel spoke the words of salvation for all mankind to the Virgin Mary. He adds that on the same day that mankind was lost on account of the fruit of the forbidden tree, so on that day Christ hangs on the tree of the Cross and wins salvation for mankind.
St. Irenaeus is the most prolific writer among the early Church Fathers. He was the spiritual son of St, Polycarp, who in turn was ordained and taught by St. John the Apostle. He emigrated from the East to Lyon (Gaul or France), advised several popes, was consecrated a bishop, fought against numerous heresies, and was ultimately martyred for the Faith. The popes of his day considered him a most reliable source for Apostolic Tradition and on that basis accepted his counsel on several important matters. Thus, in the writings of St. Irenaeus, we have a very important and trustworthy witness; and we are in direct contact with the traditions taught by the Apostles themselves. (In fact, St. Irenaeus writes that it is an apostolic tradition that Our Lord was conceived on March 25th) Those interested can read a bit more about this from Dom Guéranger's The Liturgical Year for March 25, linked here.
We have writings from a number of other Fathers and Doctors of the Church who convey this tradition, including St. Augustine, St. Clement of Alexandria, St. Cyprian, and St. Maximus the Confessor,
Once again, in this 2016th year of Our Lord, Good Friday will fall on March 25th. This is rather singular since it will only happen twice in this entire century. The other occurrence was in 2005, just a few weeks before Cardinal Ratzinger was elected Pope Benedict XVI. This means in all likelihood, most of us will never again by alive on a Good Friday that falls on March 25. (It will take 141 years for it to happen again. Incidentally, this 141 year gap will be the longest such gap in several centuries. For example, Good Friday fell on March 25th three times during the 20th century, but all prior to 1933.)
(4) Other Events. Traditions that come to us from antiquity also claim that many other key events in salvation history occurred on March 25th. For example: Cain slaying Abel, Melchisedech offering bread and wine in the presence of Abraham, Abraham's offering of Isaac, and the Crossing of the Red Sea. If this subject interests you, The Lepanto Institute has an article that goes into more detail and it can be read HERE.
Let us consider the providence of God behind these remarkable events and respond by cooperating as much as we possibly can with His grace.