I can see both sides of this. Everyone arguing that your schedule is flexible has a point...

But I also know what happens when you have a schedule like that: Everyone around you treats you like you have a flexible schedule and asks you to do things during it... And then on their downtime they expect you to join them. In other words, your flexible schedule isn't really flexible because theirs isn't.

If you try to tell them to keep the house quiet so you can work, you get a lecture about how they need to rest after work, as if you don't need to and they didn't take part of your day.

It's the kind of thing that always happens when you aren't on the same schedule as the rest of the world.