Apostolic Armenians, such as yours truly, (i.e. Orthodox) celebrate the birth and baptism of Christ on the 6th of January. Therefore, I wish a most heartfelt Merry Christmas to those so inclined.
There are websites that explain the origins of the “Armenian Christmas”, not to mention that of the Church (the Armenian Catholic and Protestant Church(es), while a minority, are nonetheless well and thriving) and postulate its various traditions. I offer the following resources to satiate your curiousity: for a concise explanation or the poignant explanation that the Armenian Church provides.