diff --git a/.github/workflows/actions.yml b/.github/workflows/actions.yml
index a57a1fcc..dc832bc9 100644
--- a/.github/workflows/actions.yml
+++ b/.github/workflows/actions.yml
@@ -13,6 +13,10 @@ on:
       **
   pull_request:
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
   build_docs:
     name: Build Docs
@@ -40,14 +44,11 @@ jobs:
     env:
       PY_COLORS: 1
     steps:
-      - name: Switch to using Python 3.10 by default
+      - name: Set up python
         uses: actions/setup-python@v4
         with:
           python-version: '3.10'
 
-      - name: Install tox
-        run: python -m pip install --user tox
-
       - name: Check out src from Git
         uses: actions/checkout@v3
         with:
@@ -69,10 +70,7 @@ jobs:
         if: >-
           github.event_name != 'create' ||
           github.event.ref_type != 'tag'
-        run: >-
-          git tag --points-at HEAD
-          |
-          xargs git tag --delete
+        run: git tag --points-at HEAD | xargs git tag --delete
 
       - name: Build and Check Package
         uses: hynek/build-and-inspect-python-package@v1
@@ -87,9 +85,7 @@ jobs:
         if: >-
           (
             github.event_name == 'push' &&
-            github.ref == format(
-              'refs/heads/{0}', github.event.repository.default_branch
-            )
+            github.ref == format('refs/heads/{0}', github.event.repository.default_branch)
           ) ||
           (
             github.event_name == 'create' &&
diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 21eea4a3..c746d7bc 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -4,74 +4,125 @@ on:
   workflow_call:
 
 jobs:
-  test_python:
-    name: ${{ matrix.python-version }}
+  test_javascript:
+    name: javascript
     runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: Use Node.js
+        uses: actions/setup-node@v3
+        with:
+          node-version: '16.x'
+      - name: Install dependencies
+        run: npm ci
+      - name: Run tests
+        run: npm run unit
+
+  test_unit:
+    name: ${{ matrix.os }} - ${{ matrix.python-version }}
+    runs-on: ${{ matrix.os }}
     strategy:
       fail-fast: false
       matrix:
+        os: [ubuntu-latest, windows-latest, macos-latest]
+        python-version: ["3.7", "3.8", "3.9", "3.10"]
         include:
-          - tox-env: "py37"
-            python-version: "3.7"
-
-#          https://github.com/pytest-dev/pytest-html/issues/585
-#          - os: windows-latest
-#            name: py37-windows
-#            python-version: 3.7
+          - os: ubuntu-latest
+            python-version: "3.10"
+            with-coverage: true
+
+          - os: ubuntu-latest
+            python-version: pypy3.9
+            tox-env: py3.9
+          - os: windows-latest
+            python-version: pypy3.9
+            tox-env: py3.9
+          - os: macos-latest
+            python-version: pypy3.9
+            tox-env: py3.9
+
+          - os: ubuntu-latest
+            python-version: 3.11-dev
+            tox-env: devel
+          - os: windows-latest
+            python-version: 3.11-dev
+            tox-env: devel
+          - os: macos-latest
+            python-version: 3.11-dev
+            tox-env: devel
 
-#          https://github.com/pytest-dev/pytest-html/issues/585
-#          - os: macOS-latest
-#            name: py37-mac
-#            python-version: 3.7
+    steps:
+      - name: Set newline behavior
+        run: git config --global core.autocrlf false
 
-          - tox-env: "py38"
-            python-version: "3.8"
+      - uses: actions/checkout@v3
 
-#          https://github.com/pytest-dev/pytest-html/issues/585
-#          - os: windows-latest
-#            name: py38-windows
-#            python-version: 3.8
+      - name: Use Node.js
+        uses: actions/setup-node@v3
+        with:
+          node-version: '16.x'
 
-#          https://github.com/pytest-dev/pytest-html/issues/585
-#          - os: macOS-latest
-#            name: py38-mac
-#            python-version: 3.8
+      - name: Install dependencies
+        run: npm ci
 
-          - tox-env: "py39"
-            python-version: "3.9"
+      - name: Build app
+        run: npm run build:ci
 
-          - tox-env: "py310"
-            python-version: "3.10"
+      - name: Set up python
+        uses: actions/setup-python@v4
+        with:
+          python-version: ${{ matrix.python-version }}
 
-#          https://github.com/pytest-dev/pytest-html/issues/585
-#          - os: windows-latest
-#            name: py39-windows
-#            python-version: 3.9
+      - name: Install tox
+        run: python -m pip install --upgrade tox
 
-#          https://github.com/pytest-dev/pytest-html/issues/585
-#          - os: macOS-latest
-#            name: py39-mac
-#            python-version: 3.9
+      - name: Run unit tests
+        if: ${{ ! matrix.tox-env && matrix.with-coverage }}
+        run: tox -e py${{ matrix.python-version }}-cov -- testing/test_unit.py
 
-          - tox-env: "pypy3"
-            python-version: "pypy3.9"
-            skip-coverage: true
+      - name: Run unit tests
+        if: ${{ ! matrix.tox-env && ! matrix.with-coverage }}
+        run: tox -e py${{ matrix.python-version }} -- testing/test_unit.py
 
-#          https://github.com/pytest-dev/pytest-html/issues/585
-#          - os: windows-latest
-#            name: pypy3-windows
-#            python-version: pypy3
+      - name: Run unit tests
+        if: ${{ matrix.tox-env }}
+        run: tox -e ${{ matrix.tox-env }} -- testing/test_unit.py
 
-           # https://github.com/pytest-dev/pytest-html/issues/482
-#          - os: macOS-latest
-#            name: pypy3-mac
-#            python-version: pypy-3.8
+      - name: Upload coverage to codecov
+        if: >-
+          ${{
+            ! github.event.schedule &&
+            matrix.with-coverage &&
+            github.repository_owner == 'pytest-dev'
+          }}
+        uses: codecov/codecov-action@v3
+        with:
+          fail_ci_if_error: true
+          files: ./coverage.xml
+          flags: tests
+          name: ${{ matrix.os }}-${{ matrix.python-version }}
+          verbose: true
 
-          - tox-env: "devel"
-            python-version: "3.11-dev"
+  test_integration:
+    name: ubuntu - ${{ matrix.python-version }}
+    needs:
+      - test_javascript
+      - test_unit
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        python-version: ["3.7", "3.8", "3.9", "3.10"]
+        include:
+          - python-version: "3.10"
+            with-coverage: true
+          - python-version: pypy3.9
+            tox-env: py3.9
+          - python-version: 3.11-dev
+            tox-env: devel
 
     steps:
-      - name: Set Newline Behavior
+      - name: Set newline behavior
         run: git config --global core.autocrlf false
 
       - uses: actions/checkout@v3
@@ -84,13 +135,13 @@ jobs:
         with:
           node-version: '16.x'
 
-      - name: Install Dependencies
+      - name: Install dependencies
         run: npm ci
 
       - name: Build app
         run: npm run build:ci
 
-      - name: Set up Python
+      - name: Set up python
         uses: actions/setup-python@v4
         with:
           python-version: ${{ matrix.python-version }}
@@ -98,20 +149,24 @@ jobs:
       - name: Install tox
         run: python -m pip install --upgrade tox
 
-      - name: Test with coverage
-        if: ${{ ! matrix.skip-coverage }}
-        run: tox -e ${{ matrix.tox-env }}-cov
+      - name: Run integration tests
+        if: ${{ ! matrix.tox-env && matrix.with-coverage }}
+        run: tox -e ${{ matrix.python-version }}-cov -- testing/test_integration.py
 
-      - name: Test without coverage
-        if: ${{ matrix.skip-coverage }}
-        run: tox -e ${{ matrix.tox-env }}
+      - name: Run integration tests
+        if: ${{ ! matrix.tox-env && ! matrix.with-coverage }}
+        run: tox -e ${{ matrix.python-version }} -- testing/test_integration.py
+
+      - name: Run integration tests
+        if: ${{ matrix.tox-env }}
+        run: tox -e ${{ matrix.tox-env }} -- testing/test_integration.py
 
       # TODO: https://github.com/pytest-dev/pytest-html/issues/481
       - name: Upload coverage to codecov
         if: >-
           ${{
             ! github.event.schedule &&
-            ! matrix.skip-coverage &&
+            matrix.with-coverage &&
             github.repository_owner == 'pytest-dev'
           }}
         uses: codecov/codecov-action@v3
@@ -121,17 +176,3 @@ jobs:
           flags: tests
           name: ${{ matrix.tox-env }}
           verbose: true
-
-  test_javascript:
-    name: mocha
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v3
-      - name: Use Node.js
-        uses: actions/setup-node@v3
-        with:
-          node-version: '16.x'
-      - name: Install Dependencies
-        run: npm ci
-      - name: Mocha Tests
-        run: npm run unit
diff --git a/docs/user_guide.rst b/docs/user_guide.rst
index 57649250..bf0c0f78 100644
--- a/docs/user_guide.rst
+++ b/docs/user_guide.rst
@@ -281,29 +281,6 @@ The following query parameters may be passed:
 * :code:`xpassed`
 * :code:`rerun`
 
-Formatting the Duration Column
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-The formatting of the timestamp used in the :code:`Durations` column can be modified by setting :code:`duration_formatter`
-on the :code:`report` attribute. All `time.strftime`_ formatting directives are supported. In addition, it is possible
-to supply :code:`%f` to get duration milliseconds. If this value is not set, the values in the :code:`Durations` column are
-displayed in :code:`%S.%f` format where :code:`%S` is the total number of seconds a test ran for.
-
-Below is an example of a :code:`conftest.py` file setting :code:`duration_formatter`:
-
-.. code-block:: python
-
-   import pytest
-
-
-   @pytest.hookimpl(hookwrapper=True)
-   def pytest_runtest_makereport(item, call):
-       outcome = yield
-       report = outcome.get_result()
-       setattr(report, "duration_formatter", "%H:%M:%S.%f")
-
-**NOTE**: Milliseconds are always displayed with a precision of 2
-
 .. _@pytest.hookimpl(tryfirst=True): https://docs.pytest.org/en/stable/writing_plugins.html#hook-function-ordering-call-example
 .. _ansi2html: https://pypi.python.org/pypi/ansi2html/
 .. _Content Security Policy (CSP): https://developer.mozilla.org/docs/Web/Security/CSP/
diff --git a/src/pytest_html/nextgen.py b/src/pytest_html/nextgen.py
index 49feb366..207eb8e2 100644
--- a/src/pytest_html/nextgen.py
+++ b/src/pytest_html/nextgen.py
@@ -45,12 +45,11 @@ def insert(self, index, html):
             self._html[index] = html
 
     class Report:
-        def __init__(self, title, duration_format):
+        def __init__(self, title):
             self._data = {
                 "title": title,
                 "collectedItems": 0,
                 "runningState": "not_started",
-                "durationFormat": duration_format,
                 "environment": {},
                 "tests": [],
                 "resultsTableHeader": {},
@@ -84,11 +83,10 @@ def __init__(self, report_path, config, default_css="style.css"):
         self._css = _process_css(
             Path(self._resources_path, default_css), self._config.getoption("css")
         )
-        self._duration_format = config.getini("duration_format")
         self._max_asset_filename_length = int(
             config.getini("max_asset_filename_length")
         )
-        self._report = self.Report(self._report_path.name, self._duration_format)
+        self._report = self.Report(self._report_path.name)
 
     @property
     def css(self):
@@ -242,6 +240,12 @@ def pytest_collection_finish(self, session):
 
     @pytest.hookimpl(trylast=True)
     def pytest_runtest_logreport(self, report):
+        if hasattr(report, "duration_formatter"):
+            warnings.warn(
+                "'duration_formatter' has been removed and no longer has any effect!",
+                DeprecationWarning,
+            )
+
         data = {
             "duration": report.duration,
             "when": report.when,
diff --git a/src/pytest_html/plugin.py b/src/pytest_html/plugin.py
index 2f166c56..4aa3f0d3 100644
--- a/src/pytest_html/plugin.py
+++ b/src/pytest_html/plugin.py
@@ -42,11 +42,6 @@ def pytest_addoption(parser):
         default=[],
         help="append given css file content to report style file.",
     )
-    parser.addini(
-        "duration_format",
-        default=None,
-        help="the format for duration.",
-    )
     parser.addini(
         "render_collapsed",
         type="bool",
diff --git a/testing/test_unit.py b/testing/test_unit.py
index e69de29b..18ed204a 100644
--- a/testing/test_unit.py
+++ b/testing/test_unit.py
@@ -0,0 +1,26 @@
+pytest_plugins = ("pytester",)
+
+
+def run(pytester, path="report.html", *args):
+    path = pytester.path.joinpath(path)
+    return pytester.runpytest("--html", path, *args)
+
+
+def test_duration_format_deprecation_warning(pytester):
+    pytester.makeconftest(
+        """
+        import pytest
+        @pytest.hookimpl(hookwrapper=True)
+        def pytest_runtest_makereport(item, call):
+            outcome = yield
+            report = outcome.get_result()
+            setattr(report, "duration_formatter", "%H:%M:%S.%f")
+    """
+    )
+    pytester.makepyfile("def test_pass(): pass")
+    result = run(pytester)
+    result.stdout.fnmatch_lines(
+        [
+            "*DeprecationWarning: 'duration_formatter'*",
+        ],
+    )
diff --git a/tox.ini b/tox.ini
index 3016156a..300ee4ef 100644
--- a/tox.ini
+++ b/tox.ini
@@ -4,7 +4,7 @@
 # and then run "tox" from this directory.
 
 [tox]
-envlist = py{37,38,39,310,py3}, docs, linting
+envlist = py{3.7, 3.8, 3.9, 3.10, py3.9}, docs, linting
 isolated_build = True
 
 [testenv]