Old style dating
In 1582 Pope Gregory XIII had reformed the calendar, then in use, known as the Julian Calendar (named after Julius Caesar).
In England and Wales, Ireland, and the British colonies, the change of the start of the year and the changeover from the Julian calendar occurred in 1752 under the Calendar (New Style) Act 1750. designation is particularly relevant for dates which fall between the start of the "historical year" (1 January) and the official start date, where different.This template is within the scope of Wiki Project Greece, a collaborative effort to improve the coverage of Greece on Wikipedia.If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.The second is that 1 January has not always been the first day of the year.Both of these conventions changed not very long ago.Treaty of Lübeck (1629), with the Gregorian day (22) directly above the Julian day (12), both before the name of the month, May. S.) are terms used in English language historical studies for two reasons.
The treaty was made between Catholic parties who had already begun using the Gregorian calendar, and Protestant parties who had not. The first reason is that the method of dating that is most widely used around the world today, the Gregorian calendar, has not always been used.
This is also known as OS (Old Style) and NS (New Style).
The Calendar Act 1752 brought about further changes.
The new Gregorian Calendar cut 10 days from the year in adjustment.
Other Catholic countries followed and adopted the Gregorian Calendar but England, being Protestant, did not.
The first converts from Old Style dates, typically found in English documents before 1752, to New Style dates. To avoid confusion, the year is assumed to begin on January 1st.