Date to CST

I just want to keep what ever the time it is. what is it converting ot

[root@test1]# echo "04-12-2018 11:45:17" | /usr/share/logstash/bin/logstash -f test.conf

{
"@version" => "1",
"completed" => 2018-12-04T17:45:17.000Z,
"message" => "04-12-2018 11:45:17",
"@timestamp" => 2019-02-22T17:44:23.267Z,
}
Difference is +6
if I do etc/GMT-6 = 2018-12-04T05:45:17.000Z, ( 6 hour behind.)

I simply just want to keep whatever this time is.
I am in "America/Chicago" timezone.