It's pretty simple: so simple I'm not giving you any code!
Think about a
for
loop:
for (a ; d ; c)
b;
a is the intialiazer: set a register to the number of elements in the array. Hint: ldi, anyone?
b is the body of code inside the loop. Hint: you will want a label before this.
c is the "move on to next value" code. Hint: is dec a month, or something else?
d is the test and branch if not complete. Hint: brne ring any bells?
Give it a try: this is not a complicated homework task!