The Christmas came to the ancient Russia together with Christianity and became one of the most important Christian holidays – in the orthodox church Christmas is the second important holiday after the Easter.
The circumstances under which there appeared two types of Christmas (catholic and orthodox) are linked with the fact that in the countries of the catholic Europe, where people had lived in the old days by the Julian calendar, the 4 October 1582 the pope Gregory XIII introduced Gregorian calendar. So one day being waked up the 4th of October, the people went to bed the 15th.
In other words the 25th of December became the 7th of January.
Before the October revolution of 1917 Russia had lived by Julian calendar and passed to Gregorian calendar only after the revolution. The church didn’t accept the revolution and stayed with the old Julian calendar.
So the date is the main difference of the orthodox Christmas. But there are also others.
First, orthodox Christmas is more spiritual, ecclesiastical holiday. 40 days before it the people keep a strict fast. In the Orthodoxy there is only one Christmas liturgy which lasts till the morning and runs as many centuries ago – all the traditions are being strictly conserved annually.
Second, the Easter is more respected by the orthodox believers than Christmas. In other words the moment of Christ resurrection is more important for them than the birth.
The traditional dish on the Christmas table is a goose with apples.
The other difference is that the Grandpa Frost brings the presents to children only on New Year night and not on Christmas.
The Christmas Eve in Russia is called Sochelnik. This day the people used to eat a special dish Sochevo – boiled wheat (or rice) with honey.
In Sochelnik it is forbidden to eat and drink before the first star. By tradition the table is covered with white tablecloth and there should be 12 Lenten dishes on it.
Also Christmas fortune-telling is widely general. In Russia and Ukraine they say that namely during the “saint” days it’s more probable to predict the future.
From the ancient days the people were singing special ritual songs called Christmas kolyadki.