I have spent few years in gambling as total period but never gave more than 3 hours in any single day to gambling. That was when i was playing roulette and slots machines because they need time and attention to play. In sports betting and I just choose option place bet and let it work by itself and I enjoy the games.
You must be very much determined with your gambling plans. Gambling only for few hours must be a good practice as you will not keep on trying again and again with your profits. Usually, I do gamble till I face losses. Most of the time, my accounts got thrown away in one or two hours of play itself based on my bank roll.
Indeed I also do not and its also not good to do it longer or after you do not have the money for it because it than can bring you in big problems.
Another thing is that this is meaning that you are getting greedy and that is a sort of addictive behavior.