A red letter day

Origin

Imagine a time before digital calendars, when every important date had to be carefully marked by hand or with special printing. The tradition of highlighting significant days in red ink dates back to ancient ecclesiastical calendars, where holy days, saints' days, and festivals were literally printed or inscribed in vermillion to distinguish them from the mundane entries in black. These 'red letter days' were not just about spiritual observance; they were also often days of rest, celebration, or special events, making them stand out in memory as much as they did on the page. From these early prayer books and printed almanacs, the phrase entered common parlance, evolving into our modern shorthand for any day of joyous or special significance.