Re:jet lag
We flew nonstop from Newark to Copenhagen, arriving at 7:30 AM (1:30 AM our body clock time). My husband was able to nap on the plane, but I wasn’t. Amazingly, I felt okay at the airport and for the first few hours at our apartment. Then I napped for about three hours. Both my husband and I had no trouble getting to sleep that evening at a normal bedtime.
Coming home was another story. I awakened at 3:30 AM for over a week!
I use this website to keep track of the length of days in Copenhagen.
https://www.timeanddate.com/sun/denmark/copenhagen?month=9&year=2015
Although the days are very short in the winter, they are very long in the summer. Our daughter felt like she had a second day ahead of her when she finished classes on a June day, and sometimes forgot to eat dinner because it never became completely dark at night. She moved to Albuquerque in July and August to do an internship, and felt she was roughing it when it became dark by 9:00 PM. LOL