red-letter day

noun
1.
a memorably important or happy occasion
Word Origin
C18: from the red letters used in ecclesiastical calendars to indicate saints' days and feasts
red-letter day in Culture

red-letter day definition


A special or memorable day; the expression refers to the old custom of printing holidays in red on calendars: “John got promoted and engaged to be married yesterday; it was truly a red-letter day for him.”

Slang definitions & phrases for red-letter day

red-letter day

noun phrase

An important day; a memorably happy or noteworthy day: red-letter days marked on the calendar


Idioms and Phrases with red-letter day

red-letter day

A special occasion, as in When Jack comes home from his tour of duty, that'll be a red-letter day. This term alludes to the practice of marking feast days and other holy days in red on church calendars, dating from the 1400s. [ c. 1700 ]