Caroline talks a lot about the past and the future, and she has specific (and consistent) ways in which she does this.
To describe something that has already happened, she says, "Last night a year ago..." As in, "Did you make me a cake for my birthday last night a year ago?"
To describe something that's going to happen, she says, "Sometime on Thursday..."
Just so you have a heads-up, that's what those phrases mean. Every once in a while, Bob gets confused and says something like, "Did you tell Caroline we're going to Chicago on Thursday?" And I say, "No, did she tell you that? ... Oh wait. I'm sure I told her we'd go to Chicago some time soon. To her, that's on Thursday." The little goober.
She does like to read, so perhaps she picked this up in the sports section.