Hierarchy
Official Church teaching and law outrank historical explanation. Historical explanation outranks devotional custom. Devotional custom outranks a Catholic Reminders practical application. A practical application is never labeled as doctrine.
If a date or a question cannot be established from the sources below, the service says it does not know.
Calendar
Celebrations, ranks, seasons, and colors are computed with romcal 3.0.0-dev.125 using the United States proper calendar (General Roman Calendar plus the U.S. proper). Romcal is open-source software, not a liturgical book. Confirm a pastoral question with your parish or the USCCB.
Holy days of obligation are not taken from romcal’s general flag. They are applied from the USCCB complementary norm to canon 1246, including the Saturday/Monday abrogation for January 1, August 15, and November 1. Saint Joseph is a solemnity and is not a U.S. holy day.
Readings
Citations are retrieved from the Catholic Readings API open index and linked to the matching USCCB daily readings page. The scripture translation is not copied or stored. The index can omit an alternate reading. When the index cannot be reached, no citation is invented.
Colors, ranks, and explanations
Color summaries follow General Instruction of the Roman Missal 346. Rank language follows the General Norms for the Liturgical Year. Catholic Why answers paraphrase the Catechism or the Code of Canon Law and link the source. They are not quotations.
What we will not do
No invented quotations from saints, popes, Scripture, or the Catechism. No claim of Vatican or USCCB endorsement.