Ok, here's what it says in VickyWicki about assimilation...
My Question is: How long is the wait before assimilation occurs? Is it different for each pop? If a new pop migrates and merges with an old pop, does the timer start over?
Ok that's more than one question but you get the idea
Assimilation is judged per POP everyday. When conditions are met and certain period has passed, assimilation will happen. Consider there is a sandglass for each POP subject of assimilation. When all sand has dropped, the POP is assimilated. Sand is refilled when you restart a saved game or ownership of the province changes. Also, the falling process can be halted by various reason.
My Question is: How long is the wait before assimilation occurs? Is it different for each pop? If a new pop migrates and merges with an old pop, does the timer start over?
Ok that's more than one question but you get the idea