File input plugin , read file between to date using ignore older

Elastic Stack Logstash
1

Hello, i want to read file in logstash which are been modify between 80 and 50 weeks ago. How can I do that?

input { 
    file { path => "x./y/*.log"
            start_position => "beginning"
            ignore_older => "80 weeks"
            file_sort_by => "last_modified"
            codec => multiline {
               pattern => "^\[%{TIMESTAMP_ISO8601}\]"
               negate => true
               what => "previous"
               auto_flush_interval => 10
        }
    }
  }