What's the difference between supper and dinner?

Well I`m from Canada and it seems to me thatdinner is at noon and supper is in the evening , until I mooved to Ontario where dinner is in the evening tey don`t even hhave supper here ... Totally loses me , so you are asking a good question ....

I always used the two words interchangeably, but my grandmother used to call it "dinner" if it was ready by 5pm or so, and "supper" if it was eaten any later than that. So I'm not sure if that was just her point of view or if it was a common definition. My household has a lot of funny words for meals, because I work days and my husband works nights, so we're always saying things like "breakinner" and because it's his breakfast and my dinner, or vice versa.