I'm working on an animated clock application for the iPhone, and I have to pivot all the 3 nodes in the view, which I have obtained in the following code:

[CATransaction begin];
[CATransaction setValue:(id)kCFBooleanTrue forKey:kCATransactionDisableActions];

clockarm.layer.anchorPoint = CGPointMake(0.0, 0.0);
[CATransaction commit];

[CATransaction begin];
[CATransaction setValue:(id)kCFBooleanFalse forKey:kCATransactionDisableActions];
[CATransaction setValue:[NSNumber numberWithFloat:50.0] forKey:kCATransactionAnimationDuration];

CABasicAnimation *animation;
animation = [CABasicAnimation animationWithKeyPath:@"transform.rotation.z"];
animation.fromValue = [NSNumber numberWithFloat:-60.0];
animation.toValue = [NSNumber numberWithFloat:2 * M_PI];
animation.timingFunction = [CAMediaTimingFunction functionWithName: kCAMediaTimingFunctionLinear];
animation.delegate = self;
[clockarm.layer addAnimation:animation forKey:@"rotationAnimation"];
animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];


[CATransaction commit];

The problem it's just rotating once, ie. only 360 degree and then stopping. I want to raotate the needles indefinitely. How would I do that?