feat: use `dateutils.relativedelta` instead of `timedelta` #46

	name: PR Checks

	on:
	pull_request:
	branches:
	- main

	jobs:

	lint-interrogate:
	runs-on: ubuntu-latest
	steps:
	- name: Checkout source code
	uses: actions/checkout@v4
	- name: Set up Python
	uses: actions/setup-python@v5
	with:
	python-version: "3.10"
	- name: Install uv
	run: curl -LsSf https://astral.sh/uv/install.sh \| sh
	# - name: Install & run interrogate
	# run: \|
	# uv pip install interrogate==1.5.0 --system
	# make interrogate
	- name: Install & run linter
	run: \|
	uv pip install ."[lint]" --system
	make lint

	test:
	strategy:
	matrix:
	os: [ubuntu-latest
	#, macos-latest
	#, windows-latest
	]
	python-version: ["3.8", "3.9", "3.10", "3.11", "3.12", "3.13"]
	runs-on: ${{ matrix.os }}
	steps:
	- name: Checkout source code
	uses: actions/checkout@v4
	- name: Set up Python ${{ matrix.python-version }}
	uses: actions/setup-python@v5
	with:
	python-version: ${{ matrix.python-version }}
	- name: Install uv
	run: curl -LsSf https://astral.sh/uv/install.sh \| sh
	- name: Install dependencies and run tests
	run: \|
	uv pip install -e ."[all,test]" --system
	make test

	doc-build:
	runs-on: ubuntu-latest
	steps:
	- name: Checkout source code
	uses: actions/checkout@v4
	- name: Set up Python
	uses: actions/setup-python@v5
	with:
	python-version: "3.10"
	- name: Install uv
	run: curl -LsSf https://astral.sh/uv/install.sh \| sh
	- name: Install dependencies and check docs can build
	run: \|
	uv pip install ."[docs]" --system
	mkdocs build -v -s

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