Logstash date filter timezone not working

[srinika (srinika siddi)]

Hi I'm working on date filter and have used timezone. I get the output but the timezone is not working. Can someone please help me?
Here's the config file

input { stdin { } }

filter
{

mutate
{
   strip => "message"
}
date {

timezone => "Asia/Kolkata"
locale => "en"
match => ["message", "yyyy-MM-dd-HH:mm:ss.SSSS"]
target => "@timestamp"


}
}
output { stdout { codec => rubydebug } }

here's the output

In the output the timezone is not same as the date i gave in the input

[Badger]

@timestamp is always UTC. You have told the date filter that your message is in the Asia/Kolkota timezone, so it moves that back by 5:30 to get to UTC. That all looks perfectly normal to me.