diff --git a/.circleci/config.yml b/.circleci/config.yml
new file mode 100644
index 0000000..911e01a
--- /dev/null
+++ b/.circleci/config.yml
@@ -0,0 +1,55 @@
+version: 2
+
+jobs:
+
+  multi-test: &multi-test
+    docker:
+      - image: ruby
+
+    working_directory: ~/repo
+
+    steps:
+      - checkout
+      - run:
+          name: Which bundler?
+          command: bundle -v
+
+      - run:
+          name: Setup Rubygems
+          command: bash .circleci/setup-rubygems.sh
+      
+      - run:
+          name: Publish to Rubygems
+          command: |
+            gem build analytics-ruby
+            gem push *.gem
+#            gem push "analytics-ruby-$(git describe --tags).gem"
+
+      - run:
+          name: 'Running E2E tests'
+          command: '.buildscript/e2e.sh'
+
+  test-2.4.3:
+    <<: *multi-test
+    docker:
+      - image: circleci/ruby:2.4.3-stretch-node
+  test-2.5.0:
+    <<: *multi-test
+    docker:
+      - image: circleci/ruby:2.5.0-stretch-node
+  test-2.6.0:
+    <<: *multi-test
+    docker:
+      - image: circleci/ruby:2.6.0-stretch-node
+  test-2.7.3:
+    <<: *multi-test
+    docker:
+      - image: cimg/ruby:2.7.3-node
+workflows:
+  version: 2
+  multi-test:
+    jobs:
+      - test-2.4.3
+      - test-2.5.0
+      - test-2.6.0
+      - test-2.7.3
\ No newline at end of file
diff --git a/.circleci/setup-rubygems.sh b/.circleci/setup-rubygems.sh
new file mode 100755
index 0000000..af7fa01
--- /dev/null
+++ b/.circleci/setup-rubygems.sh
@@ -0,0 +1,3 @@
+mkdir ~/.gem
+echo -e "---\r\n:rubygems_api_key: $RUBYGEMS_API_KEY" > ~/.gem/credentials
+chmod 0600 /home/circleci/.gem/credentials
\ No newline at end of file
diff --git a/analytics-ruby.gemspec b/analytics-ruby.gemspec
index 60d9155..27aa412 100644
--- a/analytics-ruby.gemspec
+++ b/analytics-ruby.gemspec
@@ -30,4 +30,4 @@ Gem::Specification.new do |spec|
     spec.add_development_dependency 'rubocop', '~> 0.51.0'
   end
   spec.add_development_dependency 'codecov', '~> 0.1.4'
-end
+end
\ No newline at end of file
diff --git a/lib/segment/analytics/utils.rb b/lib/segment/analytics/utils.rb
index 745a5e4..2c2d86a 100644
--- a/lib/segment/analytics/utils.rb
+++ b/lib/segment/analytics/utils.rb
@@ -65,7 +65,7 @@ def datetime_in_iso8601(datetime)
       end
 
       def time_in_iso8601(time)
-        "#{time.strftime('%Y-%m-%dT%H:%M:%S.%6N')}#{formatted_offset(time, true, 'Z')}"
+        "#{time.strftime('%Y-%m-%dT%H:%M:%S.%3N')}#{formatted_offset(time, true, 'Z')}"
       end
 
       def date_in_iso8601(date)
diff --git a/lib/segment/analytics/version.rb b/lib/segment/analytics/version.rb
index 199992a..43460ff 100644
--- a/lib/segment/analytics/version.rb
+++ b/lib/segment/analytics/version.rb
@@ -1,5 +1,5 @@
 module Segment
   class Analytics
-    VERSION = '2.4.0'
+    VERSION = '2.4.1'
   end
 end