A construction worker's ancient jotting on a wall might rewrite the history books. The wall scrawl suggests that the Roman city of Pompeii was destroyed by the eruption of Mount Vesuvius in October of AD79, two months later than historians have long believed, reports the BBC. Uncovered by archaeologists in a previously untouched area of the city, the charcoal writing perhaps left by a worker renovating a home gives the date of the work as "XVI K Nov" or 16 days before November, meaning Oct. 17 in our modern calendar, per CNN. The problem is that historical records point to an August eruption. For instance, Pliny the Younger described his uncle, Pliny the Elder, setting out from Miseno, across the Bay of Naples from Pompeii, on Aug. 24 in a rescue attempt from which he never returned.
The charcoal marking isn't the first discovery to hint at an error, though. CNN mentions previous discoveries of woolly clothing and chestnuts—items that suggest the fall rather than the summer—while Reuters adds a note about a calcified branch of autumn berries. Suggesting an actual eruption date of Oct. 24, archaeologists say that Pliny the Younger might have forgotten the real date (his account of the eruption came 25 years later) or that it could have been lost along with his original writings. It's "an extraordinary discovery," says Italy's culture minister. (It follows the first body found in decades at Pompeii.)