AngularJS：如何创建自我更新的应用程序范围变量

I am working on a small game/simulation app and I need an app-wide time variable that updates itself. It could just as well be a number variable that keeps increasing for all I care, e.g. 0..1..2..3..4 every second to represent time progress within this simulation app. (this doesn't have to be JavaScript Date Object per se)I am working on a small game/simulation app and