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
Leap week calendar full weeks (364 or 371 days). Leap week calendars vary on whether the concept of month is preserved and whether the month (if preserved) has a whole number of weeks. The Pax Calendar and Hanke-Henry Permanent Calendar (formerly the Common-Civil-Calendar-and-Time) preserve or modify the Gregorian month structure. The ISO week date and the Weekdate Dating System are examples of leap week calendars that eliminate the month. Most leap week calendars take advantage of the 400-year cycle of the Gregorian calendar, which has exactly 20,871 weeks. With 329 common years of 52 weeks plus 71 leap years of 53 weeks, leap