I'll likely be moving to the US with my family next year. We had hoped to do it over the summer, but the current timeline makes that unlikely. Do U.S. public school systems accommodate midyear entrance in any way? I realize they are all different by county, but is that a thing anywhere?
If not, what would you recommend doing? Would private instruction be worth it, or just take a year vacation and enter a year late?
Edit: Realize it sounded like I'm the student, but I'm one of the parents.
You should contact the school you'll be entering and ask them for information and suggestions. They will be in charge, after all, and probably prefer certain entry times, most likely corresponding to their natural breaks (summer, Christmas, spring).
Finally it is usually better to be an older rather than a younger student. Reason is that the brain changes rapidly during those years and the younger brain can be unprepared for some subjects. Sometimes a delay of a few months makes a difference. There's also the matter of physical development and its social implications (dating, social status, etc.). So given a choice, I'd prefer to be one of the older students.
Make sure you are in touch with the school early to get all the paperwork and other stuff figured out.
I really think you are worrying too much/overthinking things. It is very common to move in the middle of the school year. Its not like parents can say "I'd love to take that job and end this stint of unemployment, but unfortunately its August.".
Do your children speak English? It can be incredibly daunting to start in a new culture and country, and if it's a new language, it's ten times harder.
We did this. My daughter grew up in France but we moved when she was 10 to California, and even though she was fluent in English, there were some hiccups. My email is in my profile. Feel free to reach out to me.