# File lib/mail/parsers/rfc2822.rb, line 3735
    def _nt_time_of_day
      start_index = index
      if node_cache[:time_of_day].has_key?(index)
        cached = node_cache[:time_of_day][index]
        if cached
          cached = SyntaxNode.new(input, index...(index + 1)) if cached == true
          @index = cached.interval.end
        end
        return cached
      end

      i0, s0 = index, []
      r1 = _nt_hour
      s0 << r1
      if r1
        if has_terminal?(":", false, index)
          r2 = instantiate_node(SyntaxNode,input, index...(index + 1))
          @index += 1
        else
          terminal_parse_failure(":")
          r2 = nil
        end
        s0 << r2
        if r2
          r3 = _nt_minute
          s0 << r3
          if r3
            i5, s5 = index, []
            if has_terminal?(":", false, index)
              r6 = instantiate_node(SyntaxNode,input, index...(index + 1))
              @index += 1
            else
              terminal_parse_failure(":")
              r6 = nil
            end
            s5 << r6
            if r6
              r7 = _nt_second
              s5 << r7
            end
            if s5.last
              r5 = instantiate_node(SyntaxNode,input, i5...index, s5)
              r5.extend(TimeOfDay0)
            else
              @index = i5
              r5 = nil
            end
            if r5
              r4 = r5
            else
              r4 = instantiate_node(SyntaxNode,input, index...index)
            end
            s0 << r4
          end
        end
      end
      if s0.last
        r0 = instantiate_node(SyntaxNode,input, i0...index, s0)
        r0.extend(TimeOfDay1)
      else
        @index = i0
        r0 = nil
      end

      node_cache[:time_of_day][start_index] = r0

      r0
    end