diff --git a/.github/workflows/style.yaml b/.github/workflows/style.yaml
index c29928b..67543df 100644
--- a/.github/workflows/style.yaml
+++ b/.github/workflows/style.yaml
@@ -12,11 +12,11 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Clone repo
-      uses: actions/checkout@v2
+      uses: actions/checkout@v4
     - name: Set up Python
-      uses: actions/setup-python@v2
+      uses: actions/setup-python@v5
       with:
-        python-version: '3.10'
+        python-version: '3.13'
     - name: Install dependencies
       run: pip3 install black
     - name: Run style checks
@@ -26,11 +26,11 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Clone repo
-      uses: actions/checkout@v2
+      uses: actions/checkout@v4
     - name: Set up Python
-      uses: actions/setup-python@v2
+      uses: actions/setup-python@v5
       with:
-        python-version: '3.10'
+        python-version: '3.13'
     - name: Install dependencies
       run: pip install flake8
     - name: Run style checks
@@ -40,11 +40,11 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Clone repo
-      uses: actions/checkout@v2
+      uses: actions/checkout@v4
     - name: Set up Python
-      uses: actions/setup-python@v2
+      uses: actions/setup-python@v5
       with:
-        python-version: '3.10'
+        python-version: '3.13'
     - name: Install dependencies
       run: pip3 install isort[colors]
     - name: Run style checks
diff --git a/.github/workflows/tests.yaml b/.github/workflows/tests.yaml
index 86d24a2..baac459 100644
--- a/.github/workflows/tests.yaml
+++ b/.github/workflows/tests.yaml
@@ -12,11 +12,11 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Clone repo
-      uses: actions/checkout@v2
+      uses: actions/checkout@v4
     - name: Set up Python
-      uses: actions/setup-python@v2
+      uses: actions/setup-python@v5
       with:
-        python-version: '3.10'
+        python-version: '3.13'
     - name: Install dependencies
       run: pip3 install mypy pytest
     - name: Run tests
@@ -26,12 +26,12 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ['3.6', '3.7', '3.8', '3.9', '3.10']
+        python-version: ['3.9', '3.10', '3.11', '3.12', '3.13']
     steps:
     - name: Clone repo
-      uses: actions/checkout@v2
+      uses: actions/checkout@v4
     - name: Set up Python
-      uses: actions/setup-python@v2
+      uses: actions/setup-python@v5
       with:
         python-version: ${{ matrix.python-version }}
     - name: Install dependencies
@@ -39,6 +39,6 @@ jobs:
     - name: Run tests
       run: pytest --cov=. --cov-report=xml
     - name: Report coverage
-      uses: codecov/codecov-action@v2
+      uses: codecov/codecov-action@v5
       with:
         token: ${{ secrets.CODECOV_TOKEN }}
diff --git a/pyproject.toml b/pyproject.toml
index ff00e0a..85b9831 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -6,7 +6,6 @@ requires = [
 build-backend = "setuptools.build_meta"
 
 [tool.black]
-target-version = ['py35', 'py36', 'py37', 'py38', 'py39']
 color = true
 skip_magic_trailing_comma = true
 
diff --git a/setup.cfg b/setup.cfg
index 89c0c0e..ec239e8 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -15,11 +15,11 @@ classifiers =
     # Supported Python versions
     Programming Language :: Python
     Programming Language :: Python :: 3
-    Programming Language :: Python :: 3.6
-    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
+    Programming Language :: Python :: 3.13
     # Type of package
     Topic :: Office/Business :: Financial :: Accounting
     Topic :: Office/Business :: Scheduling
@@ -30,7 +30,7 @@ long_description = file: README.rst
 keywords = fiscal year, fiscal quarter, calendar, datetime
 
 [options]
-python_requires = >=3.6
+python_requires = >=3.9
 packages = fiscalyear
 
 [options.package_data]