I reckon, if you're in a hurry, it might take about 6-7 seconds to rotate em....
If you have a set of spares, it looks like a mere 3 seconds
Blink and you miss it
<iframe width="560" height="315" src="//www.youtube.com/embed/aHSUp7msCIE" frameborder="0" allowfullscreen></iframe>...