Back in my pre-aliyah days, I got permission every year from my boss to work on Christmas and New Years Day. I was the only one in the building, so I was able to install and upgrade software on all the computers, make sure the anti-virus software was working, and work on some hardware and network issues as well. I was able to use the days off in January instead, when my kids had their winter school break.
(I also worked the day after Thanksgiving as well; it became my annual office clean-up and clean-out day. I would invite my boss in the following Monday to prove to him that I actually had a floor in there!)