What is Old Style (O.S.) and New Style (N.S.)?
Q: What is Old Style (O.S.) and New Style (N.S.)?
A: Old Style (O.S.) and New Style (N.S.) are terms used for calendar dates in English language historical studies, referring to the Julian Calendar, year beginning 25 March and the Gregorian Caledar, year beginning 1 January respectively.
Q: Why did people change the calendar?
A: People realised that there was a mistake in the Julian calendar, that it adds too many leap years which caused Easter to be calculated wrongly. So they designed a new calendar with a new rule of having a leap year every four years but not if the year ended in 00 unless it could be divided evenly by 400.
Q: When did Pope Gregory XIII declare that this new calendar should be used?
A: Pope Gregory XIII declared that this new calendar should be used from 1582 onwards.
Q: Why did Protestant and Eastern Orthodox countries refuse to use the new calendar?
A: Protestant and Eastern Orthodox countries refused to use the new calendar because they refused to have the Pope tell them what to do.
Q: When did Great Britain and its colonies change over to the Gregorian Calendar?
A: Great Britain and its colonies changed over to the Gregorian Calendar in 1752.
Q: What other calendars were used around world before 1752?
A: Other countries around world such as China, Japan and Korea used lunisolar calendars before 1752.
Q: What are Latin words for O.S.?
A: The Latin words for O.S., or Old Style Dating, are stili veteris or stilo vetere which can also be shortened as stv .
