On link it tries to show when each country changed over to Gregorian Calendar, although be suspicious, it can be some help, some countries we are not sure of, others we are not with changeover, which is why with astronomy, astrology programmes they leave you to research, only leaving the 1582 date in Rome as a basis for Gregorian Calendar ruling....historical links can lead you to wrong conclusions regarding actual dates that you push in astrology programmes/astronomy programmes....historical sites don't bother with star alignment, or calcalations regarding this that is very important to us!!!
You left a link to October Revolution JUP, most links say in the Julian Calendar this happened on 25th October 1917 O/S, but we need to use 7th Nov 1917 by Gregorian Calendar.....please read...actually by using Julian Calendar, this started on 24th October 1917, by the Military Revolutionary Committee taking over of government buildings:-
https://en.wikipedia.org/wiki/October_Revolution
So real date of this revolution is 6th November 1917, to when it started,
please note download for private members on 6th Nov 1917 for Petrograde/Saint Petersburg, as Sun was rising Sirius was setting, something to think about with Lenin being Athiest!