The "stand-alone" month names ("LLLL" format) in English are expected to be identical to the "context sensitive" ("MMMM" format) month names, but instead we see only numbers. This program: import java.text.*; import java.util.*; public class September { public static void main(String[] args) throws Throwable { Date date = new SimpleDateFormat("yyyy-MM-dd").parse("2010-09-15"); String[] formats = {