Question

in_the_loop_599 an important day; a day to remember The expression originates from the practice of marking holy days in red on some calendars.

Accepted Answer

RED-LETTER DAY Tomorrow is going to be a red-letter day for our school. The president is coming to speak to the students and faculty.Mike was made a vice president of the company yesterday. It certainly was a red-letter day for him.

Id	in_the_loop_599
Idiom	RED-LETTER DAY
Definition	an important day; a day to remember
Examples	Tomorrow is going to be a red-letter day for our school. The president is coming to speak to the students and faculty. Mike was made a vice president of the company yesterday. It certainly was a red-letter day for him.
Extra Info	The expression originates from the practice of marking holy days in red on some calendars.

Day Red Letter President In The Loop 599 Important Remember Tomorrow School