Well, I'm actually asking this question in order to answer another question. xD
http://pokemondb.net/pokebase/184357/what-differences-lumiose-city-peoples-speech-different-times
I'm not sure if this is against the rules, but I doubt it is. :P
Anyhow, I'm trying to answer the above question, but my dilemma is that my Lumiose NPCs (you know, the people that you walk by and they interrupt your wonderful Lumiose stroll with their useless blurts) never change dialogue. I've checked most times of the day, but I've never seen them actually change dialogue. So at what time does the dialogue change?
I reset my 3DS time and date a week ago to do something (which ultimately failed ;_;) so if that affects anything, you've got that piece of info. I also hope this doesn't remain forever-unanswered because I don't want to add to the wonderful collection of unanswered, incomplete and somewhat useless questions please. :3