Idioms & Slang: Red Letter Day

The headline in this report from Saturday 9 May (posted by Drudge Report) is a play on words of course with the symbols of the old Soviet Union. However, a red letter day or red-letter day, with a hyphen, is a commonly used term in the English language to refer to any special day. The term in fact dates back to the medieval period when holidays, saint’s days and feast days were marked in red on church calendars as decreed in 325 by the First Council of Nicaea. However, the term became more firmly fixed in everyday language in the 16th century when the Common Book of Prayer showed special days printed in red ink.

Today, the term no longer is used as much for religious days but used to describe special events.

• The day Apollo 11 landed on the moon was a red letter day in the history of space exploration.
• When Jack comes home from his military mission overseas, that’ll be a red letter day.
• I’m really having a red letter day on my birthday, everyone came to see me and wish me “Happy Birthday.”