Add field timestamp with current time

I want to update timestamp to current time and date.
So how do I add field timestamp with current date and time.
And how to remove old timestamp.

Thank you.

Unless a message has a @timestamp field when it enters Logstash it'll create that field and initialize it with the current time. Depending on your configuration you might be able to just save that timestamp (possibly in another field).

Otherwise I think you need to use a ruby filter to create a field with the current time.

Thank. It's working. But there is one problem, how do I change timezone?
Currently it is only Z.
But I want +5.30 .

Use https://www.elastic.co/guide/en/logstash/current/plugins-filters-date.html#plugins-filters-date-timezone

Thank. It's working. But there is one problem, how do I change timezone?

The @timestamp field is by definition UTC.