If full time format, don't abbreviate the time zone.

src/kits/locale/FormattingConventions.cpp

@@ -478,8 +478,10 @@ BFormattingConventions::GetTimeFormat(BTimeFormatStyle style,
 		}
 	}
 
+	if (style != B_FULL_TIME_FORMAT) {
 		// use abbreviated timezone in short timezone format
 		CoerceFormatToAbbreviatedTimezone(outFormat);
+	}
 
 	fCachedTimeFormats[style] = outFormat;