gistfile1.txt

{:timestamp=>"2014-09-02T10:48:49.644000+0000",
:message=>"+---------------------------------------------------------+\n|
An unexpected error occurred. This is probably a bug.   |
\n|
You can find help with this problem in a few places:    |
\n
|                                                         |
\n|
* chat: #logstash IRC channel on freenode irc.          |
\n|
IRC via the web: http://goo.gl/TI4Ro                |
\n|
* email: logstash-users@googlegroups.com                |
\n|
* bug system: https://logstash.jira.com/                |\n
|                                                         |
\n+---------------------------------------------------------+\n
The error reported is: \n  The datetime zone id '%{tz}' is not recognised"
}

            if [tz] {
                date {
                    match => [ "nginx_date", "yyyy/MM/dd HH:mm:ss" ]
                    timezone => "%{tz}"
                    target => "nginx_timestamp"
                    add_tag => ["timestamp_changed"]
                }
            }