How does attack resolve in game?

Hi, I have a question, If my friend manage to lock someone sub city down with an attack like 2 to 3 hrs to hit. Can I attack that sub city and how long will the attack take to hit it. My meaning is that will my attack be behind my friends attack timing or will my attack hit that sub city first assuming my city is just next to that sub city? Hope someone can answer my question. Thank.

if you're closer, you'll get the attack first.

You only get placed behind in the queue if your attack time falls within 10 minutes of your friends arrival.