As a church kid - and by church kid, I mean my mother worked for churches - the Sunday nap was a regular event. We all enjoyed our Sunday nap. If I didn't actually sleep, I read books, which was one of my favorite activities as a little girl. I could be so engrossed by a story that my parents would have to shake me to get my attention. I have always loved the escape of a good story.
As I grew into adulthood, I still enjoyed the Sunday nap. When my kids were young, it meant all four of us piled into my bed - which was the only time the kids were allowed to sleep with us. We would all go to sleep pretty quickly, but I would get up first since DH tends to snore loudly. DS sleeps very soundly so he would continue to snooze and DD would get up after I did. She would say, "Daddy is honk-shooting and I can't sleep anymore." "Honk-shoot" was her description of snoring and I suppose if you could make the sound of a snore a word, it would be "honk-shoot."
I don't nap much anymore on Sunday but DH does still.
I still do enjoy the "no agenda" on Sunday - although I do tend to do some work, but it is at my leisure and more restful than my desk at school. So, maybe it still qualifies.
Whenever your Sabbath rest happens, make it meaningful.