gistfile1.txt

% bin/logstash -e 'filter { date { match => [ "message", "YYYY-MM-dd HH:mm:ss,SSS" ] } }'
2014-01-31 08:23:47,061
{
  "message"    => "2014-01-31 08:23:47,061",
  "@version"   => "1",
  "@timestamp" => "2014-01-31T08:23:47.061Z",
  "type"       => "stdin",
  "host"       => "oh-my"
}