How to rotate by intervals?

I’m creating a loading circle shader with a rotating gradient using a Polar Vortex node driven by Time. I would like to have this rotation snap to 30° intervals instead of smoothly animating the rotation but I’m not sure how to achieve this?

For future reference, you want the Shader Graph subforum, not the Shader subforum:

As for how to do this, any time you want to have something be stepped like this the math you want to do is this:

stepped value = floor(value / step size) * step size