diff --git a/.github/workflows/packaging_test.yml b/.github/workflows/packaging_test.yml
index d2c8a27..43841ea 100644
--- a/.github/workflows/packaging_test.yml
+++ b/.github/workflows/packaging_test.yml
@@ -6,7 +6,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        python-version: ["3.7", "3.8", "3.9", "3.10", "3.11"]
+        python-version: ["3.7", "3.8", "3.9", "3.10", "3.11", "3.12"]
         os: [ubuntu-latest]
     steps:
       - uses: actions/checkout@v4
diff --git a/.github/workflows/unittests.yml b/.github/workflows/unittests.yml
index f962770..c54280a 100644
--- a/.github/workflows/unittests.yml
+++ b/.github/workflows/unittests.yml
@@ -6,7 +6,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        python-version: [ "3.7", "3.8", "3.9", "3.10", "3.11" ]
+        python-version: ["3.7", "3.8", "3.9", "3.10", "3.11", "3.12"]
         os: [ ubuntu-latest ]
     steps:
       - uses: actions/checkout@v4
diff --git a/pyproject.toml b/pyproject.toml
index 56016cc..09327a3 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [tool.black]
 line-length = 79
-target-version = ['py37', 'py38', 'py39', 'py310', 'py311']
+target-version = ['py37', 'py38', 'py39', 'py310', 'py311', 'py312']
 exclude = '''
 /(
     \.eggs
@@ -43,7 +43,12 @@ classifiers = [
     "Operating System :: OS Independent",
     "Programming Language :: Python",
     "Programming Language :: Python :: 3 :: Only",
+    "Programming Language :: Python :: 3.7",
+    "Programming Language :: Python :: 3.8",
+    "Programming Language :: Python :: 3.9",
+    "Programming Language :: Python :: 3.10",
     "Programming Language :: Python :: 3.11",
+    "Programming Language :: Python :: 3.12",
 ]
 dependencies = [
     "holidays>=0.16,<0.28;python_version<'3.8'",
diff --git a/tox.ini b/tox.ini
index e8a4c00..c958f8f 100644
--- a/tox.ini
+++ b/tox.ini
@@ -34,6 +34,7 @@ commands =
 # the type_check environment checks the type hints using mypy
 deps =
     -r requirements.txt
+    holidays<0.34   # temporarly pinned because PR #55
     mypy
     types-pytz
     types-python-dateutil
@@ -57,6 +58,7 @@ commands =
 deps =
     {[testenv:tests]deps}
     {[testenv:linting]deps}
+    {[testenv:type_check]deps}
     {[testenv:format]deps}
     pip-tools
 commands =