I'd say Christmas Eve/Day is last minute. I'm usually done about a week before, though not always, and I start getting nervous if I go into that final week with anything not bought. But one of my most special Christmas memories was when I was working in a transitional living facility. One of the residents, a 19 year old guy, had some money come through from somewhere or other right before Christmas. Not a lot at all, but more than the zero he usually had. So he asked me to take him Christmas shopping. Late Christmas Eve night. I wasn't allowed to transport in my personal car, and I couldn't arrange a facility vehicle at that time on a holiday, but we were allowed to walk. The only thing open within walking distance was a drugstore.
Talk about finding the true meaning of Christmas! I was 18 and living with my parents, and we had a huge tree with piles of presents under it that had been there for days. But watching this guy's eyes light up as he carefully rummaged through cheap dish towels and picked-over boxes of candy to find just the right presents for his mom and brother and girlfriend...it was all I could do not to burst into tears. I used to judge people who were shopping on Christmas Eve night, especially at a drugstore. But since then, I just smile, happy that they're able to do something special for someone they love.