My Little Man went through a stage where he hated school a while back. Every day, he'd ask, "Is it school tomorrow? I don't wanna. Is it? Is it?"
I told him that we didn't have school on "S" days (days that start with the letter "S"). He'd recently learned his days of the week ... in order even!
Later that day, I looked at the calendar for something and noticed that the first letter in every day had been crossed out and replaced with an "S" ... Sonday, Suesday, Sednesday, Shursday, Sriday ... and of course, the two "real S" days. lol.
So it obviously worked.