How to keep logstash date type?

[pamiers]

I am reading data from oracle and putting data into elasticsearch through logstash.
However, when reading data from oracle, the value of the field corresponding to the Date type is automatically changed to UTC type, different from the original data.
I know that the date value is managed by UTC in elasticsearch.
The value of the original data is 2020-12-29 00:48: 00, but it automatically changes to 2020-12-28T15: 28: 00.000Z.
Therefore, logstash cannot know the original data value and cannot manipulate the data of filter-plugin.
Is there a way to keep the original data? In addition, change the original data in UTC Can yyyy-MM-dd'T'HH: mm: ss.SSS + 0900" be changed?

My logstash config is

input {
   jdbc {
        jdbc_validate_connection => true
        jdbc_driver_library => "<driver>"
        jdbc_driver_class => "Java::oracle.jdbc.OracleDriver"
        jdbc_connection_string => "<connection>"
        jdbc_user => "<user>"
        jdbc_password => "<password>"
        jdbc_paging_enabled => true
        tracking_column => "unix_ts_in_secs"
        tracking_column_type => "numeric"
        use_column_value => true
        statement =>  "SELECT * FROM table"
        schedule => "*/1 * * * *"
        charset => "UTF-8"
        enable_metric => false
        last_run_metadata_path => "path"
   }
}

filter {
        mutate {
            copy => { "id" => "[@metadata][_id]"}
            remove_field => ["id", "@version", "unix_ts_in_secs", "ip_num"]
            convert => {
                "deleted" => "boolean"
            }
        }
}

output {
        stdout {
            codec => rubydebug
        }

        elasticsearch {
            hosts => ["eshost"]
            index => "index"
            document_id => "%{[@metadata][_id]}"
        }
}

[aaron-nimocks]

Not sure if I completely understand what you are looking to do but have you looked at the date filter?

With that you can match your date input format and assign it a timezone on what to use. You can also use a new field name so you can have a formatted date field that Elastic uses and then you can maintain your old date field in which ever format you need.

[Badger]

If your database has date columns then I believe the jdbc input will convert them to date type in logstash. That will be in UTC. This post, and the links to it, may help you to adjust the timezone.