A constant in fictional world is the nonexistence of the concept of time. Bart Simpson is 10 years old since nearly 20 years and Batman celebrate is tenth years of vigil since roughly 70 years. But Disney cartoons are a notable exception. A good demonstration of this is Max Goof. Since his first appearance in the cartoons of his father Goofy, we see him grow to toddlers (early appearance) to pre-teen (Goof Troop) to teen (to young adult.
Louie, Huey and Dewey are also in the number of Disney characters we see age in Quack Pack, where they are teenagers. Already, considering they are toddler in House Of Mouse while Max is a young adult, we can establish than Goofy is the oldest of the main bunch, along with Pete whose son PJ is of the same age group than Max.
That lead us to the main course of this discourse. Time does exist in Toontowm, but at which epoch? The modern days off course, you will say, but Don Rosa would tell you wrong. He put the canonical Scrooge McDuck comic's time setting ,and therefore the one of the whole disneyverse, in....the 1950's. But if Disney cartoon are canonically set in the 1950s, where all this modern technology are coming from? And this modern fashions?
But what kind of fashions we are speaking of? Quack Pack Donald's Hawaiian shirt? Goof Troop Goofy and Pete's Bowling shirts? Quack Pack Louie, Hewey and Dewey's coat and t-shirt? All this could have existed in the 1950s. And for the technology, genius inventors like Ludwig Van Drake and Geo Gearloose could have easily provided it.In fact, its make sense than the disneyverse is set in the 1950s since the cartoons was born in the 1930s. If time exist in this universe,logically they can't go very far from it.
In conclusion, I can say without a doubt then the Disney cartoons are set in a dieselpunk version of the 1950s. In a last note, I would say than the chronology go roughly like so:
-Mickey's Clubhouse -Early Cartoons and Recent Reboot - Epic Mickey -Goofy George Goof Period
-Goof Troop -Goofy Movie -Donald's cartoon with his nephews. -House Of Mouse -Ducktales and Scrooge McDuck comics -Quack Pack