This sentence can also be used when it is not Christmas to mock someone who says irrelevant things, or for a crazy/extremely unexpected situation.
Yes, same as Καλά κρασιά :-)
that's very funny :)
Χριστούγεννα, τα Why is it plural?
Several languages have celebrations in plural -- e.g. "Saturnalia". Greek also has e.g. τα γενέθλια "birthday" which is plural.
Perhaps the underlying idea is of "celebrations" (plural) or "rites".
Ναι, τα γενέθλια, I did not think of it, celebrations then. Thank you
In Spanish it is plural too: "Navidades".