page_title: Adoption of the Gregorian calendar
section_title: Sweden
hierarchical_section_title: Adoption of the Gregorian calendar / Adoption in Protestant countries / Sweden
caption_attribution_description: English: Swedish almanack of 1753, the year when Sweden adopted the Gregorian calendar.
context_page_description: The adoption of the Gregorian Calendar was an event in the modern history of most cultures and societies, marking a change from their traditional dating system to the modern dating system that is widely used around the world today. Some states adopted the new calendar from 1582, some did not do so before the early twentieth century, and others did so at various dates between; however a number continue to use a different civil calendar. For many the new style calendar is only used for civil purposes and the old style calendar remains used in religious contexts. Today, the Gregorian calendar is the world's most widely used civil calendar. During – and for some time after – the change between systems, it has been common to use the terms Old Style and New Style when giving dates, to indicate which calendar was used to reckon them.
  The Gregorian calendar was decreed in 1582 by the papal bull Inter gravissimas by Pope Gregory XIII, to correct the erroneous assumption in the then-current Julian calendar that a year lasts 365.25 days, when in reality it is about 365.2422 days.
context_section_description: Sweden's transition to the Gregorian calendar was difficult and protracted. Sweden started to make the change from the Julian calendar and towards the Gregorian calendar in 1700, but it was decided to make the (then 11-day) adjustment gradually by excluding the leap days (29 February) from each of 11 successive leap years, 1700 to 1740. Meanwhile, the Swedish calendar would be out of step with both the Julian calendar and the Gregorian calendar for 40 years; also, the difference would not be constant but would change every four years. This system had potential for confusion when working out the dates of Swedish events in this 40-year period. To add to the confusion, the system was poorly administered, and the leap days that should have been excluded in 1704 and 1708 were not excluded. The Swedish calendar (according to the transition plan) should have been 8 days behind the Gregorian but was 10 days behind. King Charles XII recognised that the gradual change to the new system was not working, and he abandoned it.
  Rather than proceeding directly to the Gregorian calendar, it was decided to revert to the Julian calendar. This was achieved by introducing the unique date 30 February in 1712, adjusting the discrepancy in the calendars from 10 back to 11 days. Sweden finally adopted the solar portion of the Gregorian calendar in 1753, when Wednesday, 17 February, was followed by Thursday, 1 March. Since Finland was under Swedish rule at that time, it did the same. The Russian Empire's 1809 conquest of Finland did not revert this, since autonomy was granted, but government documents in Finland were dated in both the Julian and Gregorian styles. This practice ended when independence was gained in 1917.
caption: Swedish Almanach of 1753
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