1-2 hours or until i reach my target it depends of my luck..sometimes going down and crash. But in another day it doubles or it keeps on crashing - 
One to two hours per day gambling considered quite high because you may slowly addict to these games and may lose a lot of money in gambling. If possible try not to gamble every day instead just once in awhile just gamble for fun and if you're lucky then surely you will make some good money but don't gamble only to make a profit.