One of the biggest questions in the Professor Layton games is when in time do they take place?
On Hershel Layton's Twitter, it is said that the games take place between 1956 and 1967
Can't seem to find it on twitter so...
Also,Damn, Professor Layton sure loves to spam.
That is not really an official statement as ANYONE can make a Twitter about it.
I always thought Layton was set in mid 20th century France, mainly due to the architecture.
I think they mention something about conquering space in one of the games, so probably 60s.
That being said, some things are likely not meant to be thought about - it's a gaming world losely based on our own. Most likely the developers picked and chose what seemed best.