red-letter

[ red-let-er ]

adjective

1. marked by red letters, as festival days in the church calendar.
2. memorable; especially important or happy:

   a red-letter day in his life.

3. (of a Bible) having the quoted words of Jesus appear in red type:

   a red-letter edition;

   the red-letter New Testament presented at her baptism.

Word History and Origins

Origin of red-letter¹

First recorded in 1660–70

Example Sentences

This was a red-letter day in the history of Liverpool's famous old stadium as the new top deck of the Anfield Road Stand was in use for the first time.

From BBC

His 24 points - his highest tally in a Test match - included two tries, but his kicking, vision and communicative skills laid the foundation for Ireland's red-letter day.

From BBC

Saturday was a red-letter day for the history of art in Southern California.

From Los Angeles Times

It was a red-letter day for Elizebeth, proof that she had lived up to her old dreams of achievement.

From Literature

Normally he was a jovial man, with an impish sense of humor, but on that red-letter day he was clearly bummed.

From Washington Post