Why Joda DateTimeFormatter cannot parse timezone names ('z')

From DateTimeFormatter javadoc:

Zone names: Time zone names ('z') cannot be parsed.

Therefore timezone parsing like:

System.out.println(new SimpleDateFormat("EEE MMM dd HH:mm:ss z yyyy").parse("Fri Nov 11 12:13:14 JST 2010"));

cannot be done in Joda:

DateTimeFormatter dtf = DateTimeFormat.forPattern("EEE MMM dd HH:mm:ss z yyyy");
System.out.println(dtf.parseDateTime("Fri Nov 11 12:13:14 JST 2010"));
//Exception in thread "main" java.lang.IllegalArgumentExcep开发者_如何转开发tion: Invalid format: "Fri Nov 11 12:13:14 JST 2010" is malformed at "JST 2010"
//at org.joda.time.format.DateTimeFormatter.parseDateTime(DateTimeFormatter.java:673)

I think that the reason is that 'z' timezone names are conventional (not standardized) and ambiguous; i.e. they mean different things depending on your country of origin. For example, "PST" can be "Pacific Standard Time" or "Pakistan Standard Time".

If you are interested, this site has a listing of a large number of timezone names. It is not difficult to spot cases where there is ambiguity.

Probably because some time zone abbreviations are ambiguous and the parser can't know which time zone is meant.

It might of course also be one of the tiny, strange ticks and missing features you find after working with Joda for a while.

Abbreviated time zones are indeed ambiguous and Joda took a step further removing support for them as stated in the DateTimeZone javadoc: