diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index be95196bd..0a51771c1 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -2,6 +2,15 @@ name: build
 on: [push, pull_request]
 jobs:
   build:
+    services:
+      mssql:
+        image: mcr.microsoft.com/mssql/server:2022-latest
+        env:
+          SA_PASSWORD: yourStrongPassword123
+          ACCEPT_EULA: Y
+        ports:
+          - 1433:1433
+
     strategy:
       fail-fast: false
       matrix:
@@ -18,6 +27,8 @@ jobs:
     env:
       BUNDLE_GEMFILE: ${{ matrix.gemfile }}
     steps:
+      - run: sudo apt install freetds-dev freetds-bin
+      - run: echo "CREATE DATABASE groupdate_test" | tsql -H localhost -p 1433 -U sa -P yourStrongPassword123
       - uses: actions/checkout@v4
       - uses: ruby/setup-ruby@v1
         with:
diff --git a/Gemfile b/Gemfile
index 36738b718..57f921caf 100644
--- a/Gemfile
+++ b/Gemfile
@@ -10,3 +10,5 @@ gem "mysql2"
 gem "trilogy"
 gem "sqlite3", "< 2"
 gem "ruby-prof", require: false
+gem "activerecord-sqlserver-adapter"
+gem "tiny_tds"
diff --git a/Rakefile b/Rakefile
index ac691f9b2..2c478f2ea 100644
--- a/Rakefile
+++ b/Rakefile
@@ -1,7 +1,7 @@
 require "bundler/gem_tasks"
 require "rake/testtask"
 
-ADAPTERS = %w(postgresql mysql trilogy sqlite enumerable redshift)
+ADAPTERS = %w(postgresql mysql trilogy sqlite enumerable redshift sqlserver)
 
 ADAPTERS.each do |adapter|
   namespace :test do
diff --git a/gemfiles/activerecord61.gemfile b/gemfiles/activerecord61.gemfile
index 86765c598..fd16d71cb 100644
--- a/gemfiles/activerecord61.gemfile
+++ b/gemfiles/activerecord61.gemfile
@@ -9,3 +9,5 @@ gem "pg"
 gem "mysql2"
 gem "activerecord-trilogy-adapter"
 gem "sqlite3", "< 2"
+gem "activerecord-sqlserver-adapter"
+gem "tiny_tds"
\ No newline at end of file
diff --git a/gemfiles/activerecord70.gemfile b/gemfiles/activerecord70.gemfile
index e7faf9753..4e17db4ae 100644
--- a/gemfiles/activerecord70.gemfile
+++ b/gemfiles/activerecord70.gemfile
@@ -9,3 +9,5 @@ gem "pg"
 gem "mysql2"
 gem "activerecord-trilogy-adapter"
 gem "sqlite3", "< 2"
+gem "activerecord-sqlserver-adapter"
+gem "tiny_tds"
\ No newline at end of file
diff --git a/lib/groupdate.rb b/lib/groupdate.rb
index d4f83e69d..788d8dee7 100644
--- a/lib/groupdate.rb
+++ b/lib/groupdate.rb
@@ -13,6 +13,7 @@
 require_relative "groupdate/adapters/mysql_adapter"
 require_relative "groupdate/adapters/postgresql_adapter"
 require_relative "groupdate/adapters/sqlite_adapter"
+require_relative "groupdate/adapters/sqlserver_adapter"
 
 module Groupdate
   class Error < RuntimeError; end
@@ -46,6 +47,7 @@ def self.register_adapter(name, adapter)
 Groupdate.register_adapter ["Mysql2", "Mysql2Spatial", "Mysql2Rgeo", "Trilogy"], Groupdate::Adapters::MySQLAdapter
 Groupdate.register_adapter ["PostgreSQL", "PostGIS", "Redshift"], Groupdate::Adapters::PostgreSQLAdapter
 Groupdate.register_adapter "SQLite", Groupdate::Adapters::SQLiteAdapter
+Groupdate.register_adapter "SQLServer", Groupdate::Adapters::SqlServerAdapter
 
 require_relative "groupdate/enumerable"
 
diff --git a/lib/groupdate/adapters/sqlserver_adapter.rb b/lib/groupdate/adapters/sqlserver_adapter.rb
new file mode 100644
index 000000000..e72e0531a
--- /dev/null
+++ b/lib/groupdate/adapters/sqlserver_adapter.rb
@@ -0,0 +1,48 @@
+module Groupdate
+  module Adapters
+    class SqlServerAdapter < BaseAdapter
+      def group_clause
+        raise Groupdate::Error, "Time zones not supported for SQLServer" unless @time_zone.utc_offset.zero?
+        raise Groupdate::Error, "day_start not supported for SQLServer" unless day_start.zero?
+
+        query =
+          case period
+          when :minute_of_hour
+            ["CAST(DATEPART(MINUTE, #{column}) AS INT)"]
+          when :hour_of_day
+            ["CAST(DATEPART(HOUR, #{column}) AS INT)"]
+          when :day_of_week
+            ["CAST((DATEPART(WEEKDAY, #{column}) + @@DATEFIRST - 1) %% 7 AS INT)"]
+          when :day_of_month
+            ["CAST(DATEPART(DAY, #{column}) AS INT)"]
+          when :day_of_year
+            ["CAST(DATEPART(DAYOFYEAR, #{column}) AS INT)"]
+          when :month_of_year
+            ["CAST(DATEPART(MONTH, #{column}) AS INT)"]
+          when :week
+            ["CAST(DATEADD(DAY, -((DATEPART(WEEKDAY, #{column}) - 1 + @@DATEFIRST - ? + 7) % 7), #{column}) AS DATE)", week_start + 1]
+          when :quarter
+            raise Groupdate::Error, "Quarter not supported for SQLServer"
+          when :day
+            ["CAST(DATETRUNC(DAY, #{column}) AS DATE)"]
+          when :month
+            ["CAST(DATETRUNC(MONTH, #{column}) AS DATE)"]
+          when :year
+            ["CAST(DATETRUNC(YEAR, #{column}) AS DATE)"]
+          when :custom
+            ["DATEADD(SECOND, CAST(LEFT(FLOOR(DATEDIFF(SECOND, '1970-01-01', #{column}) / ?) * ?, 10) AS INT), '1970-01-01')", n_seconds, n_seconds]
+          when :second
+            ["DATETRUNC(SECOND, #{column})"]
+          when :minute
+            ["DATETRUNC(MINUTE, #{column})"]
+          when :hour
+            ["DATETRUNC(HOUR, #{column})"]
+          else
+            raise Groupdate::Error, "'#{period}' not supported for SQL Server"
+          end
+
+          @relation.send(:sanitize_sql_array, query)
+      end
+    end
+  end
+end
diff --git a/test/adapters/sqlserver.rb b/test/adapters/sqlserver.rb
new file mode 100644
index 000000000..f2afec2b4
--- /dev/null
+++ b/test/adapters/sqlserver.rb
@@ -0,0 +1,8 @@
+ActiveRecord::Base.establish_connection(
+  adapter: "sqlserver",
+  database: "groupdate_test",
+  host: "localhost",
+  port: 1433,
+  username: "SA",
+  password: "yourStrongPassword123"
+)
diff --git a/test/column_test.rb b/test/column_test.rb
index 5925275af..a079f002e 100644
--- a/test/column_test.rb
+++ b/test/column_test.rb
@@ -24,7 +24,13 @@ def test_string_function
   end
 
   def test_string_function_arel
-    assert_empty User.joins(:posts).group_by_day(Arel.sql(now_function)).count
+    if sql_server?
+      assert_raises(ActiveRecord::StatementInvalid) do
+        User.joins(:posts).group_by_day(Arel.sql(now_function)).count
+      end
+    else
+      assert_empty User.joins(:posts).group_by_day(Arel.sql(now_function)).count
+    end
   end
 
   def test_symbol_with_join
@@ -89,6 +95,8 @@ def now_function
       "datetime('now')"
     elsif redshift?
       "GETDATE()"
+    elsif sql_server?
+      "GETDATE()"
     else
       "NOW()"
     end
diff --git a/test/day_start_test.rb b/test/day_start_test.rb
index 75f2ca789..751aaae73 100644
--- a/test/day_start_test.rb
+++ b/test/day_start_test.rb
@@ -174,14 +174,14 @@ def test_decimal_start_of_day
   end
 
   def test_decimal_hour_of_day
-    skip if sqlite?
+    skip if sqlite? || sql_server?
     assert_result :hour_of_day, 23, "2013-05-04 02:29:59", false, day_start: 2.5
   end
 
   # invalid
 
   def test_too_small
-    skip "call_method expects different error message" if sqlite?
+    skip "call_method expects different error message" if sqlite? || sql_server?
 
     error = assert_raises(ArgumentError) do
       call_method(:day, :created_at, day_start: -1)
@@ -190,7 +190,7 @@ def test_too_small
   end
 
   def test_too_large
-    skip "call_method expects different error message" if sqlite?
+    skip "call_method expects different error message" if sqlite? || sql_server?
 
     error = assert_raises(ArgumentError) do
       call_method(:day, :created_at, day_start: 24)
@@ -199,7 +199,7 @@ def test_too_large
   end
 
   def test_bad_method
-    skip "call_method expects different error message" if sqlite?
+    skip "call_method expects different error message" if sqlite? || sql_server?
 
     error = assert_raises(ArgumentError) do
       call_method(:minute, :created_at, day_start: 24)
diff --git a/test/test_helper.rb b/test/test_helper.rb
index 6153bea37..7cc3cf55c 100644
--- a/test/test_helper.rb
+++ b/test/test_helper.rb
@@ -62,6 +62,10 @@ def redshift?
     ENV["ADAPTER"] == "redshift"
   end
 
+  def sql_server?
+    ENV["ADAPTER"] == "sqlserver"
+  end
+
   def create_user(created_at, score = 1)
     created_at = created_at.utc.to_s if created_at.is_a?(Time)
 
@@ -105,6 +109,10 @@ def call_method(method, field, options)
       error = assert_raises(Groupdate::Error) { User.group_by_period(method, field, **options).count }
       assert_includes error.message, "not supported for SQLite"
       skip
+    elsif sql_server? && (method == :quarter || (options[:time_zone] && options[:time_zone] != "bad") || options[:day_start] || (Time.zone && options[:time_zone] != false))
+      error = assert_raises(Groupdate::Error) { User.group_by_period(method, field, **options).count }
+      assert_includes error.message, "not supported for SQLServer"
+      skip
     else
       User.group_by_period(method, field, **options).count
     end