It's good that you aware if you're spend too much time for gambling, so you can reduce it from now on. Unfortunately not many gamblers can be like you who aware and realize that they spend too much time for gambling.
If he is still aware that he may gamble too much, it means he isn't addicted. He actually still plays in an healthy way, he knows when he gamble excessively. As long as he still realizes that he gambles too much, he will stop it temporarily when he realizes it. Sure, there are many people who aren't aware of gambling excessively. They even never understand how much money ideally to spend in gambling. These type of gamblers who probably end up with addiction case.
You probably need to find a new hobby or use that time to take a nap, so will not really feel if you have a lot free time, that would make you to spend it for gambling.
Of course, we don't only play gambling. There should be time for taking a rest and do many activities in real life. If we only focus on gambling all a day, it can be categorized addiction. If someone experience this, it is better to stop their bad gambling habit. Evaluate and get the way to minimize the time for gambling.