No use database for holidays storage

app/lib/holiday.rb

@@ -0,0 +1,19 @@
+class Holiday
+  def self.all
+    @all ||= new.all
+  end
+
+  def all
+    (year2023 + year2024).map { |date| Date.parse(date) }
+  end
+
+  private
+
+  def year2023
+    %w[2023-01-06 2023-05-01 2023-08-15 2023-10-12 2023-11-01 2023-12-06 2023-12-08 2023-12-25]
+  end
+
+  def year2024
+    %w[2024-01-01 2024-01-06 2024-05-01 2024-08-15 2024-10-12 2024-11-01 2024-12-06 2024-12-25]
+  end
+end

test/lib/holiday_test.rb

@@ -0,0 +1,15 @@
+require "test_helper"
+
+class HolidayTest < ActiveSupport::TestCase
+  test "2022-11-22 is not holiday" do
+    assert_not Holiday.all.include?(Date.parse("2022-11-22"))
+  end
+
+  test "2023-01-06 is holiday" do
+    assert_includes Holiday.all, Date.parse("2023-01-06")
+  end
+
+  test "2024-01-01 is holiday" do
+    assert_includes Holiday.all, Date.parse("2024-01-01")
+  end
+end