Red Letter Day

A red letter day (sometimes hyphenated as red-letter day or called scarlet day in academia) is any day of special significance.

The term originates from Medieval church calendars. Illuminated manuscripts often marked initial capitals and highlighted words in red ink, known as rubrics. The First Council of Nicaea in 325 decreed the saints' days, feasts and other holy days, which came to be printed on church calendars in red. The term came into wider usage with the appearance in 1549 of the first Book of Common Prayer in which the calendar showed special holy days in red ink.

Many current calendars have special dates and holidays such as Sundays, Christmas Day and Midsummer Day rendered in red colour instead of black.

On red letter days, judges of the English High Court (Queen's Bench Division) wear, at sittings of the Court of Law, their scarlet robes (See court dress). Also in the United Kingdom, other civil dates have been added to the original religious dates. These include anniversaries of the Monarch's birthday, official birthday, accession and coronation.

In the universities of the UK, red letter days are called scarlet days. On such days, doctors of the university may wear their scarlet 'festal' or full dress gowns instead of their undress ('black') gown. This is more significant for the ancient universities such as Oxford and Cambridge where academic dress is worn almost daily; the black undress gown being worn on normal occasions as opposed to the bright red gowns. Since most universities now only use academic dress on graduation day (where doctors always wear scarlet), the significance of scarlet days has all but disappeared.

In Norway, Sweden and South Korea and some Latin American countries, a public holiday is typically referred to as "red day" (rød dag, röd dag, 빨간 날), as it is printed in red in calendars.