Hello!

Gavin Kennedy wrote:
 > What is professional practice at present?

  Dk: In Russia the change of calendars was made later - in 1918 after the
bolshevik ("October") revolution of 1917. In those days the difference
amounted to 13 days, that's why after January 31 under the decree of
Sovnarkom February 14 came. Since those days all "old style" dates were
accompanied by "new style" dates (in parentheses).

  Dk: But Russian Orthodox church continued using the Julian calendar,
therefor all church feasts shifted (e.g., the Orthodox Christmas is on
January 7 which is December 25 in Old Style).

  Dk: The only problem existed is to calculate the difference correctly. In
XIV century it was equal to 9 days, in XX century - already 13. And in
European countries calendar changes took place in different years (e.g.,
in 1582 in Italy, Spain, Portugal, Poland, France, and some other
countries, in 1583 - in Bavaria, Tirol and part of Austria, in 1584 - in
other part of Austria, in Westphalia and some cantons of Switzerland.
Prussia switched to New Style in 1610, Britain in 1752. At last Turkey
changed its calendar in 1927 and Egypt in 1928).

Sincerely Yours,
Dmitry Krutikov