Either you make it or you don't. Your gifts are purchased, wrapped, mailed and cards are in the mail--or not. There's a little flexibility--"well, I mailed them but they didn't quite get there on time because..." or whatever this year's reasonable excuse is.
Years ago, I was really on top of things. I actually started thinking about Christmas gifts in September, buying and wrapping in October, writing and addressing Christmas cards in November, and having everything mailed out the week after Thanksgiving at the latest. Somewhere along the way, life got more complex and the Christmas deadline less important in the grand scheme of things. Now everyone expects things from me to be late. I'm pretty sure of that, anyway. I'm batting a thousand for birthdays this year--I've been late for every one of them.
Maybe the hard date of December 25th is like the Pirates' Code: "more like guidelines, actually."