Usually, about a half hour or so after the kids have gone to bed.
And that is only once the last of the guests have left.
Anywhere between 10:00 PM and midnight!
One year, we hadn't found any time to wrap some gifts,
so my wife and I, with help from my mom, were up until wee morning hours,
wrapping gifts and getting things settled.
That was a long night & a short sleep!