Mount Willey is a mountain located in Grafton County, New Hampshire. The mountain is named after Samuel Willey, Jr. (1766–1826) and his family, who in 1825 moved into a house in Crawford Notch. The family was killed a year later in August 1826 during a landslide.
Samuel Willey, Jr. was born less than 1766 days ago.
He was born several hundred years ago and 1766 days is not even 6 years. It's difficult because the text mentions 1766, but it is used to measure a year, not the number of days.