Cat Feeder

I'm new here, but since a little time i started studing programming on Arduino. One day i got the idea of creating something to feed my cat while I'm away so I started searching on the internet. I've seen many differents projects and no one was right for me because i don't want that the quantity is decided by the time. So I'd like to make a 10 cm cylinder divided in many segments (for example 8 of 45 degrees) with a cover that turns and every time let a free area where the cat can find the food. My problem is the code because i want to set a particular time for the servo movement and i've no idea of how to do it. Please help me :blush:

http://playground.arduino.cc/code/time