Rotate image via javascript using CSS
First of all, your code use Array.each() method, which is a non-standard Javascript method, added by Mootools. I would rather use a standard loop, in order to keep a vanilla JS code.

Then, instead of setting all properties every time, you should test which properties are supported by the browser and set them accordingly.

Finally, since you are moving minutes only when !seconds (i.e. seconds == 0), the clock initialization is a bit weird. On page load, you should always move minutes and hours.