In a normal year, the solemnity of the Annunciation would be celebrated on March 25. This day is exactly nine months before the celebration of Christmas, which occurs on December 25.
In fact, in previous centuries March 25 was a holy day of obligation.
In the past, most feasts that had the rank of solemnity were considered a holy day of obligation, requiring all Catholics to attend Mass on that day.
This was the case for the solemnity of the Annunciation on March 25, as the Catholic Encyclopedia affirms:
This feast was always a holy day of obligation in the Universal Church. As such it was abrogated first for France and the French dependencies, 9 April, 1802; and for the United States, by the Third Council of Baltimore, in 1884.
The Annunciation still remains a solemnity, but is no longer a holy day of obligation, unless a local bishops’ conference chooses to reinstate it.
Furthremore, March 25 will occasionally fall during Holy Week, which means, in the Western Church, that the liturgical celebration is suppressed.
Whenever this occurs, the liturgical observance is moved to the next available week day that is not a solemnity.
Since the week following Easter is considered “a week of solemnities,” the Annunciation gets pushed back even further.
In 2024, the Annunciation is moved from March 25 all the way to Monday, April 8.
This means that all the liturgical readings and prayers for the solemnity of the Annunciation are used on April 8, even though it is not March 25.
How to celebrate on April 8
It can be confusing, and often it can catch us off-guard. We aren't expecting to celebrate the Annunciation on April 8, especially since it is a Monday.
Mondays, especially in the United States, have become a day off for many priests, meaning that there might not be a Mass on April 8.
Many parishes will celebrate a Mass for the solemnity on Monday, especially if there is a parish school.
If your local parish does not have a Mass on April 8, then it is possible to pray the Liturgy of the Hours and use the texts for March 25.