The family's last name., My analysis.

The facts:
1. An episode in season 2, when Jim was helping Ruby with her math homework, he referred to him self as "JT" in his song.

2. An episode in season 5, when Jim was with Ruby in the school dance, he referred to Ruby as "Ruby Tuesday".

3. Jim's middle name is Orenthal.

My analysis:
The 'T' in "JT" can't be Jim's middle name since we know that it is Orenthal, he could have other names but if so, where is the 'O' for Orenthal and why use only "JT"? Jim later went on to refer to Ruby as "Ruby Tuesday", which supplies "Tuesday" for the 'T' in "JT", "Jim Tuesday". So I am led to believe that the family's last name is "Tuesday".

Ambiguity:
Calling somebody by their first name plus a pseudo last name "Tuesday" may be an American custom that I am not familiar with. I wouldn't really know.

It's been a while since I've watched the math episode, so you may be right about that. What I thought they said though was....

"My name is 18 and I'm 2x9. Man, I'm do'n fine. Really wanna get up to Heaven. 3x9 is twenty....."

"Eleven!" (Ruby's error, lol).

Ruby Tuesday was just a nickname though. It's a song reference. That was the title of a Rolling Stones song from 1967. (And also the name of a restaurant.)

I still can't believe they didn't give them a last name. Jim even said in an interview (I'm thinking on Regis & Kelly) that they were going to reveal that by the end of the series. Of course it isn't really a big deal, but it's important to me. I'm interested in little details like that.

Actually they had the perfect opportunity to do a reveal. In the recent episode where Jim had that giant check, they could've easily written his last name on there. That check, even though the big one couldn't be cashed, would've still had his full name. But they still chose to only write Jim on it.

18 -> JT, oh boy, this was a stupid mistake! I guess this is a case of "If you look hard enough, you'll find it."

@ Lewis

You said that at some point in the show, they hinted that the family's last name starts with an 'A'. What episode was that?

That was in Season 7, Episode 11; "Pregnancy Brain". There was an 'A' on their towels.....



So I assumed that was the first letter of their last name. Either that, or Jim's been snatching towels from Andy's house.