The Gregorian Calendar said nothing about it, one way or the other. The only thing Pope Gregory did was to adjust the way leap years were calculated, to skip leap years every year divisible by 100 but not by 400.
Many Protestant countries initially objected to adopting a Catholic innovation; some Protestants feared the new calendar was part of a plot to return them to the Catholic fold.
Britain and the British Empire (including the eastern part of what is now the United States) adopted the Gregorian calendar in 1752, followed by Sweden in 1753.
https://en.wikipedia.org/wiki/Gregorian_calendar
What happened, in the Virginia colony, on September 8th, 1752? (Trick question...)
NOTHING!
Try adjusting your computer’s calendar to before September 1752...