Feast days

The commemoration of the massacre of these "Holy Innocents"—considered by some Christians as the first martyrs for Christ^[17]—first appears as a feast of the western church in the Leonine Sacramentary, dating from about 485. The feast is also called Childermas, Children's Mass or Holy Innocents' Day, and is celebrated on different dates by different traditions: the Syrians and Chaldeans commemorate them on December 27; the Roman Catholic Church (using red vestments on this day since 1961, and violet or red with older missals), the Church of England and the Lutheran Church commemorate the slaughtered children on December 28; and the Eastern Orthodox Church commemorates them on December 29 (using the Julian calendar).

In Spain and Ibero-America, December 28 is a day for pranks, equivalent to April Fool's Day in many countries. Pranks are known as inocentadas and their victims are called inocentes, or alternatively, the pranksters are the "inocentes" and the victims should not be angry at them, since they could not have committed any sin. Various Catholic countries have a tradition (no longer widely observed) of role reversal between children and their adult educators, plausibly a christianized version of the Roman annual feast of the Saturnalia (when even slaves played 'masters' for a day). In some cultures it is said to be an unlucky day, when no new project should be started.