I think that it is very shortsighted to assume that your "alphabet" is only A-Z when you can support characters from other alphabets with in your code with no additional effort. Even if your applicaiton is %100 targeted to a English speaking, US audience you will run into occasions where you want to use accented characters: El Niño, Björk, Café, etc.... IMHO, limiting your code to work on A-Z only is asking for trouble later on (like using a 2 digit year). Why limit yourself when you don't have to?