diff --git a/t/04_live.t b/t/04_live.t
index e03152d..754e7d8 100644
--- a/t/04_live.t
+++ b/t/04_live.t
@@ -3,7 +3,7 @@ use warnings;
 use Test::More;
 use Test::TCP;
 use Time::Piece;
-use t::Util qw/ run_fluentd slurp_log /;
+use t::Util qw/ run_fluentd slurp_log $ENABLE_TEST_EVENT_TIME /;
 use POSIX qw/ setlocale LC_ALL /;
 use Capture::Tiny qw/ capture /;
 
@@ -25,8 +25,7 @@ subtest tcp => sub {
     ok $logger->post( $tag, { "foo" => "bar" }), "post ok";
 
     my $time     = time - int rand(3600);
-    my $time_str = localtime($time)->strftime("%Y-%m-%dT%H:%M:%S%z");
-    $time_str =~ s/(\d\d)$/:$1/; # TZ offset +0000 => +00:00
+    my $time_str = localtime($time)->strftime("%Y-%m-%dT%H:%M:%S.000000000%z");
 
     ok $logger->post_with_time( $tag, { "FOO" => "BAR" }, $time ), "post_with_time ok";
     sleep 1;
@@ -36,6 +35,28 @@ subtest tcp => sub {
     like $log => qr{\Q$time_str\E\t$tag\t\{"FOO":"BAR"\}}, "match post_with_time log";
 };
 
+subtest tcp_event_time => sub {
+    plan skip_all => "installed fluentd not supports event_time"
+        unless $ENABLE_TEST_EVENT_TIME;
+
+    my $logger = Fluent::Logger->new( port => $port, event_time => 1 );
+    isa_ok $logger, "Fluent::Logger";
+    my $tag = "test.tcp";
+    ok $logger->post( $tag, { "event_time" => "foo" }), "post ok";
+
+    my $time     = Time::HiRes::time;
+    my $time_i   = int($time);
+    my $nanosec  = sprintf("%09d", int(($time - $time_i) * 10 ** 9));
+    my $time_str = localtime($time)->strftime("%Y-%m-%dT%H:%M:%S.${nanosec}%z");
+
+    ok $logger->post_with_time( $tag, { "event_time" => "bar" }, $time ), "post_with_time ok";
+    sleep 1;
+    my $log = slurp_log $dir;
+    note $log;
+    like $log => qr{\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}\.\d{9}[+-]\d{4}\t$tag\t\{"event_time":"foo"\}}, "match post log";
+    like $log => qr{\Q$time_str\E\t$tag\t\{"event_time":"bar"\}}, "match post_with_time log";
+};
+
 subtest error => sub {
     my $logger = Fluent::Logger->new( port => $port );
     ok $logger->post( "test.error" => { foo => "ok" } );
diff --git a/t/Util.pm b/t/Util.pm
index eb2e080..5f6d2bc 100644
--- a/t/Util.pm
+++ b/t/Util.pm
@@ -4,9 +4,11 @@ use warnings;
 use File::Temp qw/ tempdir /;
 use Path::Class qw/ dir /;
 use Test::TCP;
+use version;
 
 use Exporter 'import';
-our @EXPORT_OK = qw/ streaming_decode_mp run_fluentd slurp_log /;
+our $ENABLE_TEST_EVENT_TIME;
+our @EXPORT_OK = qw/ streaming_decode_mp run_fluentd slurp_log $ENABLE_TEST_EVENT_TIME /;
 
 sub streaming_decode_mp {
     my $sock   = shift;
@@ -22,17 +24,23 @@ sub streaming_decode_mp {
 
 sub slurp_log($) {
     my $dir = shift;
-    my @file = grep { /test\.log/ } dir($dir)->children;
+    my @file = grep { !/\.meta$/ } grep { /test\.log/ } dir($dir)->children;
     return join("", map { $_->slurp } @file);
 }
 
 sub run_fluentd {
     my $fixed_port = shift;
     my $input = shift || "forward";
-    if ( system("fluentd", "--version") != 0 ) {
+    my ($v) = ( `fluentd --version` =~ /^fluentd ([0-9.]+)/ );
+    if (!$v) {
         Test::More::plan skip_all => "fluentd is not installed.";
     }
-
+    if (version->parse($v) >= version->parse("0.14.0")) {
+        Test::More::note "fluentd version $v: enabling tests for event time.";
+        $ENABLE_TEST_EVENT_TIME = 1;
+    } else {
+        Test::More::note "fluentd version < 0.14.0: disabling tests for event time.";
+    }
     my $dir = tempdir( CLEANUP => 1 );
     my $code = sub {
         my $port = shift;
@@ -64,6 +72,7 @@ _END_
 <match test.*>
   type file
   path ${dir}/test.log
+  time_format %Y-%m-%dT%H:%M:%S.%N%z
 </match>
 _END_
         exec "fluentd", "-c", "$dir/fluent.conf";
diff --git a/xt/04_pod-coverage.t b/xt/04_pod-coverage.t
index 455357f..b666299 100644
--- a/xt/04_pod-coverage.t
+++ b/xt/04_pod-coverage.t
@@ -9,5 +9,6 @@ all_pod_coverage_ok(
                             max_write_retry write_length socket_io
                             errors prefer_integer packer pending
                             connect_error_history owner_pid
+                            event_time
                           / ], },
 );
diff --git a/xt/06_benchmark.t b/xt/06_benchmark.t
index c72ca5d..eee25bb 100644
--- a/xt/06_benchmark.t
+++ b/xt/06_benchmark.t
@@ -15,7 +15,7 @@ require Number::Format;
 use_ok "Fluent::Logger";
 diag "starting benchmark...";
 for my $size ( 10, 100, 1000 ) {
-    my $n = 10000;
+    my $n = 50000;
     my $msg = "x" x $size;
     my $start  = time;
     my $logger = Fluent::Logger->new( port => $port );