diff --git a/.github/workflows/ruby.yml b/.github/workflows/ruby.yml
index 32b961b..3e6812b 100644
--- a/.github/workflows/ruby.yml
+++ b/.github/workflows/ruby.yml
@@ -15,19 +15,20 @@ jobs:
     strategy:
       matrix:
         ruby-version:
-          - '2.0'
-          - '2.1'
-          - '2.2'
           - '2.3'
           - '2.5'
           - '2.6'
-          # - '2.7'
-          # - '3.0'
+          - '2.7'
+          - '3.0'
+          - '3.1'
+          - '3.2'
+          - '3.3'
+          - '3.4'
 
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v6
     - name: Set up Ruby
-      uses: ruby/setup-ruby@0a29871fe2b0200a17a4497bae54fe5df0d973aa # v1.115.3
+      uses: ruby/setup-ruby@d697be2f83c6234b20877c3b5eac7a7f342f0d0c # v1.269.0
       with:
         ruby-version: ${{ matrix.ruby-version }}
         bundler-cache: true # runs 'bundle install' and caches installed gems automatically
diff --git a/lib/mixpanel-ruby/events.rb b/lib/mixpanel-ruby/events.rb
index fbe4b56..be653cd 100644
--- a/lib/mixpanel-ruby/events.rb
+++ b/lib/mixpanel-ruby/events.rb
@@ -55,7 +55,7 @@ def track(distinct_id, event, properties={}, ip=nil)
       properties = {
         'distinct_id' => distinct_id,
         'token' => @token,
-        'time' => Time.now.to_f,
+        'time' => (Time.now.to_f * 1000).to_i,
         'mp_lib' => 'ruby',
         '$lib_version' => Mixpanel::VERSION,
       }.merge(properties)
@@ -103,7 +103,7 @@ def import(api_key, distinct_id, event, properties={}, ip=nil)
       properties = {
         'distinct_id' => distinct_id,
         'token' => @token,
-        'time' => Time.now.to_f,
+        'time' => (Time.now.to_f * 1000).to_i,
         'mp_lib' => 'ruby',
         '$lib_version' => Mixpanel::VERSION,
       }.merge(properties)
diff --git a/lib/mixpanel-ruby/groups.rb b/lib/mixpanel-ruby/groups.rb
index 8b09e2c..42048dc 100644
--- a/lib/mixpanel-ruby/groups.rb
+++ b/lib/mixpanel-ruby/groups.rb
@@ -170,7 +170,7 @@ def delete_group(group_key, group_id, optional_params={})
     def update(message)
       data = {
         '$token' => @token,
-        '$time' =>  Time.now.to_f,
+        '$time' =>  (Time.now.to_f * 1000).to_i,
       }.merge(message)
 
       message = {'data' => data}
diff --git a/lib/mixpanel-ruby/people.rb b/lib/mixpanel-ruby/people.rb
index 8cf57ee..8bcbf34 100644
--- a/lib/mixpanel-ruby/people.rb
+++ b/lib/mixpanel-ruby/people.rb
@@ -223,7 +223,7 @@ def delete_user(distinct_id, optional_params={})
     def update(message)
       data = {
         '$token' => @token,
-        '$time' =>  Time.now.to_f,
+        '$time' =>  (Time.now.to_f * 1000).to_i,
       }.merge(message)
 
       message = {'data' => data}
diff --git a/lib/mixpanel-ruby/tracker.rb b/lib/mixpanel-ruby/tracker.rb
index 5327f71..123fa8b 100644
--- a/lib/mixpanel-ruby/tracker.rb
+++ b/lib/mixpanel-ruby/tracker.rb
@@ -165,7 +165,7 @@ def generate_tracking_url(distinct_id, event, properties={}, endpoint=nil)
       properties = {
         'distinct_id' => distinct_id,
         'token' => @token,
-        'time' => Time.now.to_f,
+        'time' => (Time.now.to_f * 1000).to_i,
         'mp_lib' => 'ruby',
         '$lib_version' => Mixpanel::VERSION,
       }.merge(properties)
diff --git a/mixpanel-ruby.gemspec b/mixpanel-ruby.gemspec
index d1c61e2..0bc5c16 100644
--- a/mixpanel-ruby.gemspec
+++ b/mixpanel-ruby.gemspec
@@ -12,10 +12,12 @@ spec = Gem::Specification.new do |spec|
   spec.homepage = 'https://mixpanel.com/help/reference/ruby'
   spec.license = 'Apache License 2.0'
 
-  spec.required_ruby_version = '>= 2.0.0'
+  spec.required_ruby_version = '>= 2.3.0'
+  spec.add_runtime_dependency 'mutex_m'
+  spec.add_runtime_dependency "base64"
 
   spec.add_development_dependency 'activesupport', '~> 4.0'
-  spec.add_development_dependency 'rake', '~> 0'
+  spec.add_development_dependency 'rake', '~> 13'
   spec.add_development_dependency 'rspec', '~> 3.0'
   spec.add_development_dependency 'webmock', '~> 1.18'
 end
diff --git a/spec/mixpanel-ruby/events_spec.rb b/spec/mixpanel-ruby/events_spec.rb
index 6d9bc20..57f6ade 100644
--- a/spec/mixpanel-ruby/events_spec.rb
+++ b/spec/mixpanel-ruby/events_spec.rb
@@ -27,7 +27,7 @@
             'mp_lib' => 'ruby',
             '$lib_version' => Mixpanel::VERSION,
             'token' => 'TEST TOKEN',
-            'time' => @time_now.to_i
+            'time' => @time_now.to_i * 1000
         }
     }]])
   end
@@ -46,7 +46,7 @@
                 'mp_lib' => 'ruby',
                 '$lib_version' => Mixpanel::VERSION,
                 'token' => 'TEST TOKEN',
-                'time' => @time_now.to_i
+                'time' => @time_now.to_i * 1000
             }
         }
     } ]])
diff --git a/spec/mixpanel-ruby/groups_spec.rb b/spec/mixpanel-ruby/groups_spec.rb
index 063c4d8..877f42a 100644
--- a/spec/mixpanel-ruby/groups_spec.rb
+++ b/spec/mixpanel-ruby/groups_spec.rb
@@ -23,7 +23,7 @@
         '$token' => 'TEST TOKEN',
         '$group_key' => 'TEST GROUP KEY',
         '$group_id' => 'TEST GROUP ID',
-        '$time' => @time_now.to_i * 1000,
+        '$time' => (@time_now.to_f * 1000).to_i,
         '$set' => {
             '$groupname' => 'Mixpanel',
             '$grouprevenue' => 200
@@ -39,7 +39,7 @@
         '$token' => 'TEST TOKEN',
         '$group_key' => 'TEST GROUP KEY',
         '$group_id' => 'TEST GROUP ID',
-        '$time' => @time_now.to_i * 1000,
+        '$time' => (@time_now.to_f * 1000).to_i,
         '$set' => {
             'created_at' => '2013-01-02T03:04:05'
         }
@@ -54,7 +54,7 @@
         '$token' => 'TEST TOKEN',
         '$group_key' => 'TEST GROUP KEY',
         '$group_id' => 'TEST GROUP ID',
-        '$time' => @time_now.to_i * 1000,
+        '$time' => (@time_now.to_f * 1000).to_i,
         '$set' => {
             'created_at' => '2013-01-02T02:04:05'
         }
@@ -70,7 +70,7 @@
         '$token' => 'TEST TOKEN',
         '$group_key' => 'TEST GROUP KEY',
         '$group_id' => 'TEST GROUP ID',
-        '$time' => @time_now.to_i * 1000,
+        '$time' => (@time_now.to_f * 1000).to_i,
         '$set' => {
             'created_at' => '2013-01-02T02:04:05'
         }
@@ -86,7 +86,7 @@
         '$token' => 'TEST TOKEN',
         '$group_key' => 'TEST GROUP KEY',
         '$group_id' => 'TEST GROUP ID',
-        '$time' => @time_now.to_i * 1000,
+        '$time' => (@time_now.to_f * 1000).to_i,
         '$set_once' => {
             '$groupname' => 'Mixpanel',
             '$grouprevenue' => 200
@@ -102,7 +102,7 @@
         '$token' => 'TEST TOKEN',
         '$group_key' => 'TEST GROUP KEY',
         '$group_id' => 'TEST GROUP ID',
-        '$time' => @time_now.to_i * 1000,
+        '$time' => (@time_now.to_f * 1000).to_i,
         '$remove' => {
             'Albums' => 'Diamond Dogs'
         }
@@ -117,7 +117,7 @@
         '$token' => 'TEST TOKEN',
         '$group_key' => 'TEST GROUP KEY',
         '$group_id' => 'TEST GROUP ID',
-        '$time' => @time_now.to_i * 1000,
+        '$time' => (@time_now.to_f * 1000).to_i,
         '$union' => {
             'Albums' => ['Diamond Dogs']
         }
@@ -130,7 +130,7 @@
         '$token' => 'TEST TOKEN',
         '$group_key' => 'TEST GROUP KEY',
         '$group_id' => 'TEST GROUP ID',
-        '$time' => @time_now.to_i * 1000,
+        '$time' => (@time_now.to_f * 1000).to_i,
         '$unset' => ['Albums']
     }]])
   end
@@ -141,7 +141,7 @@
         '$token' => 'TEST TOKEN',
         '$group_key' => 'TEST GROUP KEY',
         '$group_id' => 'TEST GROUP ID',
-        '$time' => @time_now.to_i * 1000,
+        '$time' => (@time_now.to_f * 1000).to_i,
         '$unset' => ['Albums', 'Vinyls']
     }]])
   end
@@ -152,7 +152,7 @@
         '$token' => 'TEST TOKEN',
         '$group_key' => 'TEST GROUP KEY',
         '$group_id' => 'TEST GROUP ID',
-        '$time' => @time_now.to_i * 1000,
+        '$time' => (@time_now.to_f * 1000).to_i,
         '$delete' => ''
     }]])
   end
diff --git a/spec/mixpanel-ruby/tracker_spec.rb b/spec/mixpanel-ruby/tracker_spec.rb
index cf32bd3..1fe54eb 100644
--- a/spec/mixpanel-ruby/tracker_spec.rb
+++ b/spec/mixpanel-ruby/tracker_spec.rb
@@ -29,7 +29,7 @@
       'mp_lib' => 'ruby',
       '$lib_version' => Mixpanel::VERSION,
       'token' => 'TEST TOKEN',
-      'time' => @time_now.to_i
+      'time' => @time_now.to_i * 1000
     }
     expected_data = {'event' => event, 'properties' => properties.merge(default_properties)}
 
@@ -61,7 +61,7 @@
       with { |req| body = req.body }
 
     message_urlencoded = body[/^data=(.*?)(?:&|$)/, 1]
-    message_json = Base64.strict_decode64(URI.unescape(message_urlencoded))
+    message_json = Base64.strict_decode64(CGI.unescape(message_urlencoded))
     message = JSON.load(message_json)
     expect(message).to eq({
         'event' => 'TEST EVENT',
@@ -71,7 +71,7 @@
             'mp_lib' => 'ruby',
             '$lib_version' => Mixpanel::VERSION,
             'token' => 'TEST TOKEN',
-            'time' => @time_now.to_i
+            'time' => @time_now.to_i * 1000
         }
     })
   end
@@ -94,7 +94,7 @@
               'mp_lib' => 'ruby',
               '$lib_version' => Mixpanel::VERSION,
               'token' => 'TEST TOKEN',
-              'time' => @time_now.to_i
+              'time' => @time_now.to_i * 1000
             }
           }
         ],
@@ -106,7 +106,7 @@
                 'mp_lib' => 'ruby',
                 '$lib_version' => Mixpanel::VERSION,
                 'token' => 'TEST TOKEN',
-                'time' => @time_now.to_i
+                'time' => @time_now.to_i * 1000
               }
             },
             'api_key' => 'API_KEY',