Momzilla said:
I also thought they observed a different date for the feast of the Nativity.
In Orthodoxy there are two calendars--the Old Calendar and the New Calendar.
The Old Calendar is the Julian Calendar, the calendar everyone used before the Gregorian calendar was devised. Most Orthodox outside the United States use this calendar. The Julian and Gregorian calendars are slightly off from each other--at the present time, the difference is about 13 days.
Example time: My patron saint reposed on October 20th, 1462. New Calendar Orthodox, like me, will celebrate St. Matrona's day on the Gregorian October 20th. The Old Calendar Orthodox are 13 days behind, so they will celebrate the same saint 13 days later, on the Gregorian November 2nd.
Gregorian November 2nd = Julian October 20th
The Old Calendar Orthodox still recognize December 25th as the Nativity, but they won't
get to December 25th until we're already on January 7th. So that's why we have "Eastern Orthodox Christmas" marked on calendars as January 7th. That's Christmas on their calendar because it's their December 25th.
Most Orthodox outside the United States use the Old Calendar, but most within the United States use the New Calendar. (Suzannah and prodromos are exceptions to this--Suzannah is in the USA but her parish is Old Calendar. Prodromos lives in Greece but his parish is New Calendar.)
My church, and most Orthodox in North America, are New Calendar, so I celebrate Christmas on the Gregorian December 25th, same as my Protestant and Catholic brethren.
I know this probably seems kind of silly, arguing over a stupid calendar. I'm just glad, though, that the Orthodox argue over stupid things like this, instead of whether or not Jesus really rose from the dead. :o
For your original post, since I didn't grow up Orthodox I'm not really qualified to answer that. One of my good friends, though, was chrismated at the age of five when his family converted, and he is very, very American! (His obsession with baseball bears that out.

) He is probably more than familiar with the idiosyncrasies of growing up Orthodox, so I will ask him for you.