w3cdtf

# File lib/rss/rss.rb, line 6
      def w3cdtf(date)
        if /\A\s*
            (-?\d+)-(\d\d)-(\d\d)
            (?:T
            (\d\d):(\d\d)(?::(\d\d))?
            (\.\d+)?
            (Z|[+-]\d\d:\d\d)?)?
            \s*\z/ix =~ date and (($5 and $8) or (!$5 and !$8))
          datetime = [$1.to_i, $2.to_i, $3.to_i, $4.to_i, $5.to_i, $6.to_i]
          usec = 0
          usec = $7.to_f * 1000000 if $7
          zone = $8
          if zone
            off = zone_offset(zone, datetime[0])
            datetime = apply_offset(*(datetime + [off]))
            datetime << usec
            time = Time.utc(*datetime)
            time.localtime unless zone_utc?(zone)
            time
          else
            datetime << usec
            Time.local(*datetime)
          end
        else
          raise ArgumentError.new("invalid date: #{date.inspect}")
        end
      end