I'm not 100% sure but I think that I ring my gong every 12 hours. I say that because when I turn my game off at night by the afternoon I can ring it again. I have rang the gong quite a few times.
I do have a problem though. Everyone else that rings the gong gets some kind of event either good or bad. I have yet to get any. One way or the other.
I must have something wrong. But my games perfectly fine. Except my 2nd game. I can't pick up my beetles or butterflies.
I have all my collectables in the 1st game and all my Tech points. I have 115 villagers, that is as high as I have been able to get.I have had a few minor details but nothing annoying. Except I would like to get something for the ringing of the gong.