//Seconds to Parameter
msc = DSCore.DateTime.Components(dtm)["second"];
prm = msc>30?(60-msc)/30:msc/30;
//Curve
crv = NurbsCurve.ByPoints(Point.ByCoordinates
([0,10,-10,5],[0,10,5,-5],[0,10,5,0]));
//Sphere
sph = Sphere.ByCenterPointRadius(crv.PointAtParameter(prm),2);