[Bug classpath/28549] New: SimpleDateFormat's timezone output wrong

[andrew at operationaldynamics dot com]

The current parsing of TimeZones and formatting by SimpleDateFormat has some
problems. The result of SimpleDateFormat's "zzz" time zone short code
formatting string is completely wrong

The correct output should be as follows:

$ java TimeZoneBugs
For zone named:                                         America/Montreal
SimpleDateFormat("zzz") must be a 3 [or 4] char code:   EDT

For zone named:                                         Australia/Sydney
SimpleDateFormat("zzz") must be a 3 [or 4] char code:   EST

For zone named:                                         Europe/Paris
SimpleDateFormat("zzz") must be a 3 [or 4] char code:   CEST


Trying JamVM 1.4.3 and classpath 0.91, we get the following output:

$ jamvm TimeZoneBugs
For zone named:                                         America/Montreal
SimpleDateFormat("zzz") must be a 3 [or 4] char code:   Eastern Daylight Time
(CA)

For zone named:                                         Australia/Sydney
SimpleDateFormat("zzz") must be a 3 [or 4] char code:   GMT+10:00

For zone named:                                         Europe/Paris
SimpleDateFormat("zzz") must be a 3 [or 4] char code:   Central European
Daylight Time

Note that the timezone codes are a) inconsistent and b) not short!

Trying GCJ 4.1.1, the inconsistent output isn't present, but we still get
incorrect output:

$ gcj TimeZoneBugs.java -o TimeZoneBugs --main=TimeZoneBugs
$ ./TimeZoneBugs
For zone named:                                         America/Montreal
SimpleDateFormat("zzz") must be a 3 [or 4] char code:   GMT-04:00

For zone named:                                         Australia/Sydney
SimpleDateFormat("zzz") must be a 3 [or 4] char code:   GMT+10:00

For zone named:                                         Europe/Paris
SimpleDateFormat("zzz") must be a 3 [or 4] char code:   GMT+02:00

As an aside, "GMT+hh:mm" is format you can pass to the concrete implementation
of TimeZone called SimpleTimeZone which can be used for custom zones in the
rare event what you actually want isn't available from system. In classpath's
case we apparently generate these (from an import? at runtime?) but this is a
shame because SimpleTimeZone loses a lot of information (it doesn't understand
historical timezone shifts, for instance). While GMT+hh:mm is a valid (if
slightly useless) timezone name, it is NOT the correct value for the short
code.

AfC


-- 
           Summary: SimpleDateFormat's timezone output wrong
           Product: classpath
           Version: unspecified
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: classpath
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: andrew at operationaldynamics dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28549