Hi all. I’m using the logstash-output-opensearch . It’s working, but I can’t get it to use my log timestamp as @timestamp .

This is what I want it to use, direct from the log:
"ACTUAL_TIME": "2023-09-03T08:06:51.946Z"

This is my logstash.conf filter:

filter{
  	date {
  		match => [ "ACTUAL_TIME", "yyyy-MM-dd HH:mm:ss.SSSZ" ]
  		remove_field => [ "ACTUAL_TIME" ]
In discover, I see both fields, and they don’t match on the milliseconds:

Any help would be, like, really helpful!  
Maybe somethign like this
filter {
  mutate { remove_field => [ "field1", "field2", "field3", ... "fieldN" ] }
filter {
  	 mutate { remove_field => [ "ACTUAL_TIME"]  		
Is it posible  to show your full Logstash config.
              
Thank you for responding!
This is the full (anonymized) logstash.conf.  Note “contextMap” now prepends ACTUAL TIME.  The “_app” above was to rename it.  But still, it’s not working.
input {
   file {
     path => "/spring/logs/myApp/ELK/myLog.log"
filter{
    json{
    	source => "message"
  	date {
  		match => [ "contextMap.ACTUAL_TIME", "yyyy-MM-dd HH:mm:ss.SSSZ" ]
  		remove_field => [ "contextMap.ACTUAL_TIME" ]
}output {
    opensearch {
        hosts => "http://myServer:9200"
        user => "XXXXX"
        password => "XXXXX"
        index => "my-app-%{[agent.version]}-%{+yyyy.MM.dd}"
        ssl_certificate_verification => false
              
OK.  This issue seems to be with inner JSON.  I told it to just remove “host”, and that works.
We are sending the Log4j2 MDC map, which generates a section like this:
	"contextMap": {
		"ACTUAL_TIME": "2023-09-03T08:06:51.946Z",
Does anyone know of a way to remove just ACTUAL_TIME?  I’ve tried all combinations I can think of.
Thanks!