Adoption of the Gregorian calendar 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. Through enactment of the Calendar (New Style) Act 1750, Great Britain and its colonies (including the eastern part of what is now the United
Adoption of the Gregorian calendar decree expressly limited the reform to lay (i.e. non-religious) matters, as did the Greek decree. None of these reforms affected the dates of religious holidays. (See below.) While the civil administrations of eastern European countries adopted the Gregorian calendar in the 1910s or early 1920s, none of the national Eastern Orthodox Churches have recognised the Gregorian calendar for church or religious purposes. Instead, a Revised Julian calendar was proposed in May 1923 at the . It uses a different leap year rule, modifying a proposal of 1785 in such a way as to maximise the time before its dates start