The Dates Switch

As I was just reading through the ‘Border Papers’ it occurred to me that there are some facts about dates that we need to remember when researching our Border Reiver ancestors.

Old Style (O.S.) and New Style (N.S.) are terms sometimes used with dates to indicate that the calendar convention used at the time described is different from that in use at the time the document was being written. There were two calendar changes in Great Britain and its colonies, which may sometimes complicate matters: the first was to change the start of the year from Lady Day (25 March) to 1 January; the second was to discard the Julian calendar in favour of the Gregorian calendar. Closely related is the custom of dual dating, where writers gave two consecutive years to reflect differences in the starting date of the year, or to include both the Julian and Gregorian dates.

Beginning in 1582, the Gregorian calendar replaced the Julian in Roman Catholic countries. This change was implemented subsequently in Protestant and Orthodox countries, usually at much later dates. In England and Wales, Ireland, and the British colonies, the change to the start of the year and the changeover from the Julian calendar occurred in 1752 under the Calendar (New Style) Act 1750. In Scotland, the legal start of the year had already been moved to 1 January (in 1600), but Scotland otherwise continued to use the Julian calendar until 1752.

When recording British history it is usual to use the dates recorded at the time of the event,[a] with the year adjusted to start on 1 January. But the start of the Julian year was not always 1 January, and was altered at different times in different countries (see New Year’s Day in the Julian calendar).

From 1155 to 1752, the civil or legal year in England began on 25 March (Lady Day) so for example the execution of Charles I was recorded at the time in parliament as happening on 30 January 1648 (Old Style). In newer English language texts this date is usually shown as “30 January 1649” (New Style). The corresponding date in the Gregorian calendar is 9 February 1649, the date by which his contemporaries in some parts of continental Europe would have recorded his execution.

The O.S./N.S. 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 was 25 March in England, Wales and the colonies until 1752.

During the years between the first introduction of the Gregorian calendar in continental Europe and its introduction in Britain, contemporary usage in England started to change. In Britain 1 January was celebrated as the New Year festival, but the “year starting 25th March was called the Civil or Legal Year, although the phrase Old Style was more commonly used.” To reduce misunderstandings about the date, it was normal in parish registers to place a new year heading after 24 March (for example “1661”) and another heading at the end of the following December, “1661/62”, a form of dual dating to indicate that in the following few weeks the year was 1661 Old Style but 1662 New Style. Some more modern sources, often more academic ones, also use the “1661/62” style for the period between 1 January and 25 March for years before the introduction of the Gregorian calendar in England. Scotland had already partly made the change: its calendar year had begun on 1 January since 1600.