it does not state in the details that nose length is limited to 1 char, only which the valid chars are...
might suggest adding these additional details to clarify

Your code is wrong, not a kata issue, print the input to help you debug your code:

Array
(
    [0] => :---)
    [1] => ))
    [2] => ;~~D
    [3] => ;D
)

There, there is only one valid smiley face, and your code returns 3. Nose is optional, but either there is one char or there isn't, --- and ~~ aren't valid noses.

Well, the input is defined strictly as 1000 ≤ year ≤ 9000.