14 September - British calendar in line with the Gregorian calendar

 

The British Empire adopted the Gregorian calendar, but the process of adoption was not as straightforward as simply switching calendars on a specific date.

The Gregorian calendar was introduced by Pope Gregory XIII in 1582 as a reform of the Julian calendar, which had been in use for centuries. The Gregorian calendar was designed to bring the date of the spring equinox closer to March 21 and to better align the calendar year with the solar year.

However, it took many years for the Gregorian calendar to be adopted by various countries and regions. In the case of the British Empire, the calendar change did not occur until the 18th century. The British Empire, including its American colonies, transitioned from the Julian calendar to the Gregorian calendar in September 1752.

The transition was implemented by the Calendar (New Style) Act 1750, also known as An Act for Regulating the Commencement of the Year; and for Correcting the Calendar now in Use. According to this act, the day following September 2, 1752, was designated as September 14, 1752, in order to bring the British calendar in line with the Gregorian calendar. This adjustment involved skipping 11 days to make up for the discrepancy between the two calendars.

So, while it is correct to say that the British Empire adopted the Gregorian calendar in September 1752, the transition involved a specific adjustment to the calendar to correct the discrepancy between the Julian and Gregorian systems, resulting in the omission of 11 days from the calendar.