Time zone#The value of time zone GET default() should be based on the systems Property "user time zone", which would be set by the JVM.
But at least in earlier JDK versions it was frequently not set. Additionally time zone GET default() uses a its own default value, which was in JDK 1.1.3 "PST" (North American Pacific time zone) and was changed afterwards on “GMT” (Greenwich Mean Time).
Starting from JDK 1,2 use of DATE, simple DATE format and Calendar returned the the default time zone and locale. The source of the default TimeZone various with implementation.
Before Calendar was set in simple DATE format on first local time belt resources (e.g. in the USA on “PST”). This uncertainty can be easily avoided with: myDateFormat.setTimeZone (time zone GET default ());