A vacationing family sitting around the campfire has the following conversation:
Father: What day is it? I am sure it isn't Tuesday, Wednesday or Thursday.
Mother: Well that's not very helpful dear. Besides yesterday was Friday.
Father: No, now that i think about it, yesterday wasn't Friday, tomorrow is Friday.
Jon: The day after tomorrow is Thursday.
Meg: You are nuts. Tomorrow is Thursday.
Mother: Actually, it's probably Thursday today.
Jon: All we know for sure is that it wasn't Sunday yesterday.
If only one statement is true, what day of the week is it?