I'm from Spain and I'd say: how late we apparently eat. I'm used to having lunch at 14-15h and dinner at 21-22h, sometimes later if I don't have to wake up early the following day. Every single time I travel to another european country and I have to eat dinner at like 19:30 or earlier my stomach gets so confused, because that's usually the time I'm eating merienda (a snack before dinner time). It's not easy to adapt!
I think in Portugal they also have dinner at 21h or so, shout out to my Iberian siblings 😀
Tell me how your country differentiates from others, I'm curious!