Do you work on your startup or side projects on holidays? What sort of work do you look to get done on these days?
Holidays are a great time to work on side projects I think. Many of my side projects are actually just mental breaks from "real" work so perfect for holidays. I think it is important to find a balance though so you can actually recover on holiday also? If I do any work on holiday I try to do it in the morning so that I can spend time with my family later in the day.
Since I have a full-time day job, I find holidays to be a great time to get a focused programming day in with few interruptions.