Huh. Maybe it wasn't a reference to what I thought it was. Let's just say that a while ago I had the rather annoying habit of answering people who asked the time by repeating their question back to them. I assumed that whoever this was drew from the same source, although I now relize I may have been mistaken. (It really is that obscure...)

The thing I was thinking of was this really obscure RPG from more than a decade ago called Continuum (Tvtropes page Wikipedia page Official (semi-abandoned) website) in which time travveler's identify one another by one asking the other for the time, and then the other repeating the question right back. Thus, time-travellers can identify one another, while at worst confusing normal people with strange demands for the time or weird non-answers to the question of what the time is.

So, the obvious thing for a fan to do in order to try to identify nearby time-travelers is to go around asking a lot of people what the time is or answering such questions with the time-traveller recognized response.

As I said, very obscure.