Why Do We Call it a Red Letter Day?

When something pretty auspicious happens (or is about to happen) you might have heard it referred to as a “red letter day.” Thinking about it for about five seconds, that probably seems a little odd, since when has anyone ever sent you a red letter on an important day? But sure, let’s play ball. Why do we call it a red letter day?

It’s Way More Literal Than You Might Think

The idea of the “red letter day” dates back to the Roman republic, between 509 and 27 BC. Back then, important days were literally marked down on calendars in red. Medieval manuscripts share this as well, where points of emphasis were often written in red. These marked words were called rubrics, and date back to at least the 13th century. Oftentimes rubrics were used to highlight the first capital of something—like a psalm. They were also often used as section headers or for the names of important people (who were often religious figures at the time). Imagine if the bolded text we used between sections was in red.

Nowadays, red letter days are often reserved for public holidays when the phrase isn’t being used as an idiom. You might see them referred to as “red days” thanks to the original practice of marking public holidays on calendars in red.

 When Did We Start Calling Them Red Letter Days?

While the practice dates back to, probably, earlier than the 13th century, the earliest documented codification of the red-letter-practice we could find is found in Caxton’s Eneydos (1490). In it, we find that “red letters are still used to signify feasts in our calendars and to head psalms and chapters.” Which really just spells out the rubric stuff we talked about earlier. 

The phrase “red letter day” appears in Religio Medici (1643). In English that roughly means “The Religion of the Doctor.” While the spelling isn’t the same thanks to Old English, holy days are literally referred to as red letter days; with “the Red-letter daies being the Ornament of her Year.”

Secular use of the phrase dates back to at least 1704, in The Journals of Madam Knight. The text was published in 1825, but it’s a print of a diary kept by a woman named Sarah Kemble Knight in 1704; it mostly chronicles her journey from Boston to New York (and back). In the journals, the day in which a governor is chosen is referred to as a red letter day. 

Speaking of red things, see if you know your red literature here.