Political Acceptance in Europe

  The new calendar was adopted at once by France, Spain,
  Italy, Portugal, and Luxembourg.  By 1584, Belgium, parts
  of the Netherlands, Switzerland, and most Catholic German
  states had joined, and by 1587, so had Hungary.  It was not
  until 1699-1700 that these countries were joined by the rest
  of the Netherlands, Denmark, and the Protestant German
  countries.

  By the time the British imposed the calendar on all its
  possessions, in 1752, 11 days needed to be lost.  September 2,
  1752, was thus decreed to be followed by September 14.  In
  addition, New Year's day was moved back from March 25 to
  January 1.  (For example, before, March 24, 1700 had been
  followed by March 25, 1701).  Among other repercussions,
  this moved Washington's birth date from February 11, 1731,
  to February 22, 1732.  The following year, 1753, Sweden too
  adopted the calendar.

  In 1793, the French Revolutionary government adopted a
  calendar of 12 months of 30 days each, with 5 extra days in
  September (6 on leap years).  The Gregorian calendar was
  reinstated in 1806 by Napoleon.

  Additional topics:

  *   Political Acceptance World Wide

  *   Religious Acceptance Worldwide

  *   Brief History of the Gregorian Calendar

  *   Julian Period

  *   History and DECwindows Calendar