Failed parsing date, linux syslog

Hello, Everyone

I'm having problems to parse field timestamp, it shoud be something simple but I'm not getting to see!
I'm already here trying resolve this all day

log example:

Mar 8 03:34:15 fw01 block-INPUT IN=wan0 OUT= MAC=00:00:00:00:00:e3:10:f3:00:00:00:81:08:00 SRC=11.11.11.11 DST=22.22.22.22 LEN=48 TOS=00 PREC=0x00 TTL=119 ID=17927 DF PROTO=TCP SPT=0000 DPT=0000 SEQ=1837860932 ACK=0 WINDOW=8192 SYN URGP=0 MARK=1

config logstash:

input {
    stdin {type => "iptables"}
}

filter {
        if [type] == "iptables" {
        grok {
                        patterns_dir => "/opt/logstash/patterns"
                        match => { "message" => "%{IPTABLES}" }
            }

        date {
                        locale => "pt-BR"
                        match => [ "timestamp", "MMM  d HH:mm:ss", "MMM dd HH:mm:ss" ]
                        timezone => "America/Sao_Paulo"
            }
        }
    }

output {

    stdout {
            codec => "rubydebug"
        }
}

patterns:

NETFILTERMAC %{COMMONMAC:dst_mac}:%{COMMONMAC:src_mac}:%{ETHTYPE:ethtype}
ETHTYPE (?:(?:[A-Fa-f0-9]{2}):(?:[A-Fa-f0-9]{2}))
IPTABLES %{SYSLOGTIMESTAMP:timestamp}\s+%{HOSTNAME:source_host}\s+(?<chain>[A-Za-z0-9_-]+)?.*IN=%{WORD:in_interface}?.*OUT=(%{WORD:out_interface})?.*MAC=%{NETFILTERMAC}?.*SRC=%{IP:src_ip}?.*DST=%{IP:dst_ip}?.*TTL=%{INT:ttl}?.*PROTO=%{WORD:protocol}?.*SPT=%{INT:src_port}?.*DPT=%{INT:dst_port}

Output:

Failed parsing date from field {:field=>"timestamp", :value=>"Mar  8 03:34:15", :exception=>"Invalid format: \"Mar  8 03:34:15\"", :config_parsers=>"MMM  d HH:mm:ss,MMM dd HH:mm:ss", :config_locale=>"pt-BR", :level=>:warn}
{
         "message" => "Mar  8 03:34:15 fw01 block-INPUT IN=wan0 OUT= MAC=00:00:00:00:00:e3:10:f3:00:00:00:81:08:00 SRC=11.11.11.11 DST=22.22.22.22 LEN=48 TOS=00 PREC=0x00 TTL=119 ID=17927 DF PROTO=TCP SPT=0000 DPT=0000 SEQ=1837860932 ACK=0 WINDOW=8192 SYN URGP=0 MARK=1",
        "@version" => "1",
      "@timestamp" => "2016-03-16T11:21:20.368Z",
            "type" => "iptables",
            "host" => "logstash01.srsp.dpf.gov.br",
       "timestamp" => "Mar  8 03:34:15",
     "source_host" => "fw01",
           "chain" => "block-INPUT",
    "in_interface" => "wan0",
         "dst_mac" => "00:00:00:00:00:e3",
         "src_mac" => "10:f3:00:00:00:81",
         "ethtype" => "08:00",
          "src_ip" => "11.11.11.11",
          "dst_ip" => "22.22.22.22",
             "ttl" => "119",
        "protocol" => "TCP",
        "src_port" => "0000",
        "dst_port" => "0000",
            "tags" => [
        [0] "_dateparsefailure"
    ]
}

Thanks!

Are your sure about this parameter, as your date seems to be english, you should prefer the locale => "en" config no?

I'd forgotten that, thank you! =D