Every year we see a number of messages reminding us that Christmas is not in the Vaishnava calendar. The interesting fact is that it was not originally in the Christian calendar either.
Originally, what we now call Christmas was a traditional holiday in the Roman empire, called Dies solis invicti nati (The birthday of the invincible sun), which as one can guess, was a pagan festival dedicated to the sun. That was a day when people used to feast and exchange gifts. Due to the festival’s popularity, earlier Christians thought it wise to merge the date into their faith, choosing it as the date of the birth of Jesus (since the exact date is unknown), instead of trying to suppress it. People still exchanged presents, and so on, but now the date was related to the birth of Jesus Christ.
As Vaishnavas, we face a similar choice. Christmas is extremely popular in Western cultures, and most devotees see the need to observe it to some extent due to social or familial connections. Even if one doesn’t care much about Christmas, he may end up putting presents under the tree because of his parents, nephews, etc. To try to suppress Christmas can also be a problem for the children in our movement since it’s hard for them to see everyone else getting presents while they don’t get any. Therefore, although devotees in renounced life may see Christmas as just another nonsense, devotees in family life may have valid reasons to observe it to a certain extent.
We face thus the same choice earlier Christians in dealing with the festival of Dies solis invicti nati. We may try to ignore it and gradually try to suppress it, which may not work as intended, or we may just adopt the date, using the day to celebrate some Vaishnava festival, so devotees can associate the date with Krsna Consciousness, instead of just a consumerist festival. The date of Gita Jayanti, for example, falls quite close to Christmas and could be an option, since Gita Jayanti is also a very festive occasion, and is associated with giving out presents (in this case the best present of all).
It’s important to notice that the main point about Vaishnava festivals is the spiritual connection with great personalities or important spiritual events, and such connection is achieved by remembering such personalities and events, and not just a calendar date. There is controversy about whether the dates of the Bhisma Panchaka and the Gita Jayanti are chronologically correct anyway, but this is not important, since the benefit is in remembering and observing it.