@timestamp one day earlier than Event timestamp

Elastic Stack Logstash
1

strong text
@timestamp one day earlier (20 hours) than Event timestamp

Kibana is displaying the Document in CDT, the Event received is in EDT and @timestamp is in UTC.
When Logstash collects the message below, the time is "Tue Mar 21 11:40:00 EDT 2018".
Rubydebug displays the field timestamp as "timestamp" => "Tue Mar 21 11:40:00 EDT 2018".
The Kibana Document displays the field timestamp as "? timestamp Tue Mar 21 11:40:00 EDT 2018"
The timestamp field complains "No cached mapping for this field. Refresh field list from Management > Index Patterns page."
The timestamp field is not listed on the Index Patterns page and no amount of refreshing will make it appear.
The problem in question it that the @timestamp field displays a date 20 hours earlier than the Event occurred, "@timestamp" => "2018-03-20T15:40:00.000Z".
Because of the strange date format the date.pattern was created to parse the timestamp and is listed below.
I know you have helped others. Maybe you can decipher this one.

message:
<><><><> [Tue Mar 21 11:40:00 EDT 2018] AUDITLOGS Backup Success.5-11:40

date.pattern file:
AUDIT_MONTHDAY (?:(?:[0 ][1-9])|(?:[12][0-9])|(?:3[01])|[1-9])
DATE_AUDIT %{DAY}%{SPACE}%{MONTH}%{SPACE}%{AUDIT_MONTHDAY}%{SPACE}%{TIME}%{SPACE}%{TZ}%{SPACE}%{YEAR}
DATE_TZ %{DATESTAMP:timestamp}%{SPACE}%{TZ}

Filter:
if "_grokparsefailure" in [tags] {
grok {
patterns_dir => ["/home/dplrgid8/logstash/dev/bin/patterns"]
match => { "message" => "^<><><><>%{SPACE}[%{DATE_AUDIT:timestamp}]%{SPACE}%{GREEDYDATA:narrative}" }
remove_tag => ["_grokparsefailure"]
add_field => [ "tags", "grok25098" ]
}
date {
match => [ "timestamp", "EEE MMM dd HH:mm:ss zzz yyyy" ]
}
}

Rubydebug Output:

{
"@timestamp" => "2018-03-20T15:40:00.000Z",
"message" => "<><><><> [Tue Mar 21 11:40:00 EDT 2018] AUDITLOGS Backup Success.5-11:40 ",
"@version" => "1",
"path" => "/home/dplrgid8/logstash/data360/logs/Backup_Audit.log",
"host" => "FQDN",
"type" => "Backup_Audit",
"application" => "Data_360_-_Find",
"component" => "MARIA_DB",
"environment" => "qa",
"logstash_version" => "2.4.0",
"filter_date" => "2018/03/21 10:38:36 CDT",
"geoip" => {
"location" => {
"lat" => "LAT",
"lon" => "-LON"
}
},
"tags" => [
[0] "grok25098"
],
"timestamp" => "Tue Mar 21 11:40:00 EDT 2018",
"narrative" => "AUDITLOGS Backup Success.5-11:40 "
}

Kibana Document:
March 20th 2018, 10:40:00.000 Data_360_-_Find
MARIA_DB
FQDN
- - AUDITLOGS Backup Success.5-11:40
Backup_Audit
Link to /dplr-qa-logstash-2018.03.20/Backup_Audit/AWJJOc3GNltr8GYV7Vm7

Table
JSON

@timestamp March 20th 2018, 10:40:00.000
t @version 1
t _id AWJJOc3GNltr8GYV7Vm7
t _index dplr-qa-logstash-2018.03.20

_score -

t type Backup_Audit
t application Data_360-_Find
t component MARIA_DB
t environment qa
t filter_date 2018/03/21 10:38:36 CDT
geoip.location {
"lat": "LAT",
"lon": "-LON"
}
t host FQDN
t logstash_version 2.4.0
t message <><><><> [Tue Mar 21 11:40:00 EDT 2018] AUDITLOGS Backup Success.5-11:40
t narrative AUDITLOGS Backup Success.5-11:40
t path /home/dplrgid8/logstash/data360/logs/Backup_Audit.log
t tags grok25098
? timestamp Tue Mar 21 11:40:00 EDT 2018
t type Backup_Audit

2

Hmm. According to the documentation, timezone names like EDT can't be parsed (they're ambiguous) so I'm a bit surprised you're getting anything at all.

3

March 21st is a Wednesday. Setting the EEE to Tue is forcing it back to the 20th.

It appears to interpret EDT as Etc/GMT+4. If that's not the right EDT, then a mutate+gsub could switch in the right timezone identification (which might require using ZZZ rather than zzz).

4

3/22/2018
Sorry for the slow response but I think I have a solution based on your fabulous input.
I broke the DATE_AUDIT patten down to it's component parts. Substituted the EDT for the Java Time Zone ID, US/Eastern and then built the time stamp using add_field, leaving out the %{day} component.
Changed the timestamp match to ZZZ, as you recommended.

            if "_grokparsefailure" in [tags] {
                    grok {
                            patterns_dir => ["/home/dplrgid8/logstash/dev/bin/patterns"]
                            ### match => { "message" => "^<><><><>%{SPACE}\[%{DATE_AUDIT:timestamp}\]%{SPACE}%{GREEDYDATA:narrative}" }
                            match => { "message" => "^<><><><>%{SPACE}\[%{DAY:day}%{SPACE}%{MONTH:month}%{SPACE}%{AUDIT_MONTHDAY:monthday}%{SPACE}%{TIME:time}%{SPACE}%{TZ:tz}%{SPACE}%{YEAR:year}\]%{SPACE}%{GREEDYDATA:narrative}" }
                            remove_tag => ["_grokparsefailure"]
                            add_field => [ "tags", "grok25397" ]
                    }

                    mutate {
                            gsub => [
                                    # Replace Time Zone with Java Time Zone ID
                                    "tz", "EDT", "US/Eastern",
                                    "tz", "EST", "US/Eastern",
                                    "tz", "CDT", "US/Central",
                                    "tz", "CST", "US/Central",
                                    "tz", "MDT", "US/Mountain",
                                    "tz", "MST", "US/Mountain",
                                    "tz", "PDT", "US/Pacific",
                                    "tz", "PST", "US/Pacific"
                            ]

                            add_field => { "timestamp" => "%{month} %{monthday} %{time} %{tz} %{year}" }
                    }

                    date {
                            match => [ "timestamp", "MMM dd HH:mm:ss ZZZ yyyy" ]
                    }
            }

Rubydebug Output:

Pipeline main started
{
      "@timestamp" => "2018-03-21T16:00:00.000Z",
         "message" => "<><><><> [Wed Mar 21 12:00:00 EDT 2018] DUMP Backup Success Mar 21 12:00:00 US/Eastern 2018",
        "@version" => "1",
            "path" => "/home/dplrgid8/logstash/data360/logs/Backup_DUMP.log",
            "host" => "FQDN",
            "type" => "Backup_DUMP",
     "application" => "Data_360_-_Find",
       "component" => "MARIA_DB",
     "environment" => "qa",
"logstash_version" => "2.4.0",
     "filter_date" => "2018/03/21 16:47:49 CDT",
           "geoip" => {
    "location" => {
        "lat" => "37.66",
        "lon" => "-122.096839"
    }
  },
            "tags" => [
    [0] "grok25397"
  ],
             "day" => "Wed",
           "month" => "Mar",
        "monthday" => "21",
            "time" => "12:00:00",
              "tz" => "US/Eastern",
            "year" => "2018",
       "narrative" => "DUMP Backup Success Mar 21 12:00:00 US/Eastern 2018",
       "timestamp" => "Mar 21 12:00:00 US/Eastern 2018"
}

In Kibana @timestamp display in CDT, 11 AM in this case, is the correct date and time:

March 21st 2018, 11:00:00.000	Data_360_-_Find
MARIA_DB	FQDN
 - 	 - 	DUMP Backup Success Mar 21 12:00:00 US/Eastern 2018
Backup_DUMP
Link to /dplr-qa-logstash-2018.03.21/Backup_DUMP/AWJOd3BfdxJQCSK05ofa

Table
JSON

@timestamp 		March 21st 2018, 11:00:00.000
t @version 		1
t _id 		AWJOd3BfdxJQCSK05ofa
t _index 		dplr-qa-logstash-2018.03.21
 _score 		 - 
t _type 		Backup_DUMP
t application 		Data_360_-_Find
t component 		MARIA_DB
? day 		Wed
t environment 		qa
t filter_date 		2018/03/21 16:47:49 CDT
geoip.location 		{
  "lat": "37.66",
  "lon": "-122.096839"
}
t host 		FQDN
t logstash_version 		2.4.0
t message 		<><><><> [Wed Mar 21 12:00:00 EDT 2018] DUMP Backup Success Mar 21 12:00:00 US/Eastern 2018
? month 		Mar
? monthday 		21
t narrative 		DUMP Backup Success Mar 21 12:00:00 US/Eastern 2018
t path 		/home/dplrgid8/logstash/data360/logs/Backup_DUMP.log
t tags 		grok25397
? time 		12:00:00
? timestamp 		Mar 21 12:00:00 US/Eastern 2018
t type 		Backup_DUMP
? tz 		US/Eastern
? year 		2018

Thanks for kick starting my brain. I never would have thought about dismantling the date's component parts if you had not mentioned it.