diff --git a/pkgs/development/python-modules/whenever/default.nix b/pkgs/development/python-modules/whenever/default.nix
new file mode 100644
index 000000000000..20d05c8bbaf3
--- /dev/null
+++ b/pkgs/development/python-modules/whenever/default.nix
@@ -0,0 +1,64 @@
+{ lib
+, fetchFromGitHub
+, pythonOlder
+, buildPythonPackage
+, poetry-core
+, backports-zoneinfo
+, tzdata
+, pytestCheckHook
+, pytest-mypy-plugins
+, hypothesis
+, freezegun
+}:
+
+buildPythonPackage rec {
+  pname = "whenever";
+  version = "0.3.4";
+  pyproject = true;
+
+  disabled = pythonOlder "3.8";
+
+  src = fetchFromGitHub {
+    owner = "ariebovenberg";
+    repo = "whenever";
+    rev = version;
+    hash = "sha256-pVbR9KYothEPJUhvFA3hDnLcKp7hvU8ntxvkYrKxQfQ=";
+  };
+
+  postPatch = ''
+    # unrecognized arguments since we don't use pytest-benchmark in nixpkgs
+    substituteInPlace pytest.ini \
+      --replace-fail '--benchmark-disable' '#--benchmark-disable'
+  '';
+
+  nativeBuildInputs = [
+    poetry-core
+  ];
+
+  propagatedBuildInputs = [
+    tzdata
+  ] ++ lib.optionals (pythonOlder "3.9") [
+    backports-zoneinfo
+  ];
+
+  pythonImportsCheck = [ "whenever" ];
+
+  nativeCheckInputs = [
+    pytestCheckHook
+    pytest-mypy-plugins
+    hypothesis
+    freezegun
+  ];
+
+  # early TDD, many tests are failing
+  # TODO: try enabling on bump
+  doCheck = false;
+
+  meta = with lib; {
+    description = "Strict, predictable, and typed datetimes";
+    homepage = "https://github.com/ariebovenberg/whenever";
+    changelog = "https://github.com/ariebovenberg/whenever/blob/${src.rev}/CHANGELOG.rst";
+    license = licenses.mit;
+    maintainers = with maintainers; [ pbsds ];
+  };
+}
diff --git a/pkgs/top-level/python-packages.nix b/pkgs/top-level/python-packages.nix
index bdd6908c95fe..3c2562bb99f9 100644
--- a/pkgs/top-level/python-packages.nix
+++ b/pkgs/top-level/python-packages.nix
@@ -16300,6 +16300,8 @@ self: super: with self; {
 
   wheezy-template = callPackage ../development/python-modules/wheezy-template { };
 
+  whenever = callPackage ../development/python-modules/whenever { };
+
   whichcraft = callPackage ../development/python-modules/whichcraft { };
 
   whirlpool-sixth-sense = callPackage ../development/python-modules/whirlpool-sixth-sense { };