time2str (TMail::TextUtils)

    # File lib/action_mailer/vendor/tmail-1.1.0/tmail/utils.rb, line 189
        def time2str( tm )
          # [ruby-list:7928]
          gmt = Time.at(tm.to_i)
          gmt.gmtime
          offset = tm.to_i - Time.local(*gmt.to_a[0,6].reverse).to_i

          # DO NOT USE strftime: setlocale() breaks it
          sprintf '%s, %s %s %d %02d:%02d:%02d %+.2d%.2d',
                  WDAY[tm.wday], tm.mday, MONTH[tm.month],
                  tm.year, tm.hour, tm.min, tm.sec,
                  *(offset / 60).divmod(60)
        end