While investigating this question I stumbled upon DateFormatSymbols.getLocalPatternChars(). The javadoc just says
Gets localized date-time pattern characters. For example: 'u', 't', etc.
So I was wondering how any use of this method can be made, if there is no guarantee about the returned string. For example it could return the pattern chars in decreasing order, era to second for example (as it seems to currently do in oracle JVM, see implementation of SimpleDateFormat
)