describe that Time#strftime supports %:z and %::z.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@29150 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

NEWS

@@ -26,6 +26,10 @@ with all sufficient information, see the ChangeLog file.
     * new methods:
       * String#prepend
 
+  * Time
+    * extended methods:
+      * Time#strftime supports %:z and %::z.
+
 * io/console
   * new methods:
     * IO#noecho {|io| }