When I was a kid, I could have my stocking as soon as I woke up, but everything else was off limits until after breakfast and chores, so mid morning. I had a friend who had his the day before and they celebrated Christmas by taking the tree down. That always seemed mean to me, I don't know why.
Now we hold off until after breakfast. It's not the same with just the two of us. We don't tend to buy much for each other - all I've gotten TBG this year is socks. Whee! We prefer our money goes towards trips now. It was fun when Mom and Dad joined us - the living room would be full of paper and the cats thought they were in heaven.