When is the 下一个 few Hatsune Miku concerts?

I miss the first one in SF because I was at Washington DC and the 下一个 one in LA I missed because my sister said, "I didn't want to want to pay for something that should be fee. I mean we already payed for the convention." She made me so pissed,>.< that's why I need to know when the 下一个 in America is!XD