I agree with feeding every 2 or 3 days in warmer water and once or twice a week in cooler conditions with adult snakeheads. Young growing fish need more to keep up a good growth rate. I wouldn't leave it any longer than 2 days. A good feed every day works for me.
My brother also keeps snakeheads, he feeds them a smaller amount twice a day.
It's up to you at the end if the day, I'm sure we all do things slightly different