Great Britain shifted to the Gregorian calendar in 1752. The year 1751 was a short year (282 days) running from 25 March to 31 December. 1752 was also short of 11 days.
Spain, Italy and France shifted to the Gregorian calendar in 1582, Greece shifted in 1922, Russia shifted to Gregorian calendar in 1918. Many countries didn't shift to Gregorian calendar until recent time.