How "Next" is Next-Day?

Daniel often asks me in the evening whether I'll be staying home the following day, with great hopes in the affirmative. I usually mention the day of the week, and give some indication as to what that means for whether I'll be at work or home with him. Of course, with the Thanksgiving break, he got a quadruple-dose of having Daddy at home. This past Saturday night, he wanted to check as to how long that trend would continue:

"Daddy, next day, will you be home?"

I answered, "Yes, tomorrow I'll be here."

Daniel followed up to verify the precise time-frame:

"So next-day is tomorrow?"

(November 26, 2011)