@moonbus saidSo how many days are they behind by now?
... to the Russian Orthodox (who still use the Julian calendar).
https://www.thehindu.com/news/international/why-are-russians-celebrating-christmas-on-january-7-explained/article69056975.ece
You know this is the reason why the Revolution of 1917 is known as the October Revolution when it should be the November Revolution.