Europeans stood in America in 1021 – dated to the exact year.
At L'Anse aux Meadows in Newfoundland the Ingstads excavated eight Norse buildings from 1961 onward. In 2021 a study dated three wood finds to the year 1021: a cosmic event in 993 left a carbon marker in every tree, and the rings after it can simply be counted.
Useful: One shared time marker in wood turns 'roughly eleventh century' into a single year.
Source: en.wikipedia.org