All of this would be very easy for me to get used to, except that 21:00 dinner time. As a result, when it comes to socializing, I would lean towards having lunch with friends, not dinner.
As much as I know that there are people who love to nap, I can't do that. When it's daytime, I like to be awake. So in the evening I wind down. I head to bed right around the time that they are having dinner.
There are times when you need to adjust to the different ways of another country and there are times when you have to recognize the way your own body works. You make them fit together as well as you can.