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.