def parse_time(value, event_time, tag)
      @timestamp_parser.call(value)
    rescue => e
      router.emit_error_event(@timestamp_parse_error_tag, Fluent::Engine.now, {'tag' => tag, 'time' => event_time, 'format' => @timestamp_key_format, 'value' => value}, e)
      return Time.at(event_time).to_time