Holy Innocents Day

Feast of the Holy Innocents, also called Childermas, or Innocents’ Day, festival celebrated in the Christian churches in the West on December 28 and in the Eastern churches on December 29 and commemorating the massacre of the children by King Herod in his attempt to kill the infant Jesus (Matthew 2:16–18). These children were regarded by the early church as the first martyrs, but it is uncertain when the day was first kept as a saint’s day. At first it may have been celebrated with Epiphany, but by the 5th century it was kept as a separate festival. In Rome it was a day of fasting and mourning.
In the 1962 Roman Catholic calendar, the violet vestments for Holy Innocents were eliminated (red used instead), and if December 28 fell on Sunday, this feast was commemorated on the Sunday within the Octave of Christmas. This was changed in a later revision of the Church calendar.

In Spain, Hispanic America and the Philippines, December 28 is a day for pranks, equivalent to April Fool's Day in many countries. Pranks (bromas) are also known in Spain 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. One of the more famous of these traditions is the annual 'Els Enfarinats' festival of Ibi in Alicante, where the inocentadas dress up in full military dress and incite a flour fight. Various Catholic countries had a tradition (no longer widely observed) of role reversal between children and their adult educators, including boy bishops, perhaps 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.

In addition, there was a medieval custom of refraining where possible from work on the day of the week on which the feast of 'Innocents Day' had fallen for the whole of the following year until the next Innocents Day. This was presumably mainly observed by the better-off. Philippe de Commynes, the minister of King Louis XI of France tells in his memoirs how the king observed this custom, and describes the trepidation he felt when he had to inform the king of an emergency on the day.