This actual exchange is fabricated (too much was going on to remember it exactly), but this conversation actually took place, roughly as follows:
A: He's going to be gone from the fifth to the fourteenth.
C: Does that mean you're going to be back on the fourteenth, or the fifteenth?
B: Square bracket. (gestures)
C: So you're back on the fourteenth?
B: No, it's inclusive. Closed bracket is inclusive.
D: His vacation lasts through, and including, the fourteenth.
B: So I'll be back on the fifteenth.
C: But isn't that round bracket?
E: You mean parentheses?
B: No, not parentheses. Square bracket is inclusive. I'm gone through the fourteenth, and I'll be back on the fifteenth.
C: Oh. Got it.
A: Glad we got that cleared up.