>>27275800You have your own reward timer, which resets every 20/21 hours. It's at the top right corner of this screen, and will start counting down as soon as you place a Pokemon in a gym. Even if that specific Pokemon gets taken out, the timer will still count down so as long as you have any Pokemon in a gym by the time it reaches 0, you'll be able to get your 10 coins and 500 dust.
