On This Day: Dies Ater—Rome’s Black Day
April 27: The Romans called this a dies ater—a day so unlucky, even lawsuits were banned.

Gian Lorenzo Bernini — "Bacchanal: A Faun Teased by Children" (ca. 1616–17), public domain
A day so unlucky, business stopped.
On April 27, ancient Romans marked a dies ater, literally a ‘black day.’ No public business. No courts. The very date was a warning—Rome had suffered a disaster on this day, and to tempt fate by acting as usual was unthinkable.
A calendar of omens and memory.
Dies ater dates marked everything from military defeats to ominous eclipses. The biggest: the defeat at the Caudine Forks, forever branding certain days as cursed. This wasn’t superstition at the fringe—it was stamped on official calendars and shaped the city’s rhythm.
The dies ater—the "black day"—etched Rome's defeats and disasters into the calendar, ensuring fate and memory tangled with daily life.