refactor: Replace pytz with stdlib zoneinfo and drop Python 3.7–3.9

.github/workflows/ci.yml

@@ -14,7 +14,7 @@ jobs:
     strategy:
       max-parallel: 6
       matrix:
-        python-version: ['3.7', '3.8', '3.9', '3.10', '3.11', '3.12']
+        python-version: ['3.10', '3.11', '3.12', '3.13']
     steps:
       - uses: actions/checkout@v3
       - name: Set up Python ${{ matrix.python-version }}

README.rst

@@ -17,7 +17,7 @@ Python job scheduling for humans. Run Python functions (or any other callable) p
 - In-process scheduler for periodic jobs. No extra processes needed!
 - Very lightweight and no external dependencies.
 - Excellent test coverage.
-- Tested on Python and 3.7, 3.8, 3.9, 3.10, 3.11, 3.12
+- Tested on Python and 3.10, 3.11, 3.12, 3.13
 
 Usage
 -----

docs/faq.rst

@@ -42,12 +42,6 @@ It might be that your IDE uses a different Python interpreter installation.
 
 Still having problems? Use Google and StackOverflow before submitting an issue.
 
-ModuleNotFoundError: ModuleNotFoundError: No module named 'pytz'
-----------------------------------------------------------------
-
-This error happens when you try to set a timezone in ``.at()`` without having the `pytz <https://pypi.org/project/pytz/>`_ package installed.
-Pytz is a required dependency when working with timezones.
-To resolve this issue, install the ``pytz`` module by running ``pip install pytz``.
 
 Does schedule support time zones?
 ---------------------------------

docs/index.rst

@@ -17,7 +17,7 @@ Python job scheduling for humans. Run Python functions (or any other callable) p
 - In-process scheduler for periodic jobs. No extra processes needed!
 - Very lightweight and no external dependencies.
 - Excellent test coverage.
-- Tested on Python 3.7, 3.8, 3.9, 3.10, 3.11 and 3.12
+- Tested on Python 3.10, 3.11, 3.12 and 3.13
 
 
 :doc:`Example <examples>`

docs/installation.rst

@@ -6,17 +6,15 @@ Python version support
 ######################
 
 We recommend using the latest version of Python.
-Schedule is tested on Python 3.7, 3.8, 3.9, 3.10, 3.11 and 3.12
+Schedule is tested on Python 3.10, 3.11, 3.12 and 3.13
 
 Want to use Schedule on earlier Python versions? See the History.
 
 
 Dependencies
 ############
 
-Schedule has 1 optional dependency:
-
-Only when you use ``.at()`` with a timezone, you must have `pytz <https://pypi.org/project/pytz/>`_ installed.
+Schedule has no external dependencies. Timezone support uses Python's built-in :mod:`zoneinfo` module.
 
 Installation instructions
 #########################

docs/timezones.rst

@@ -6,22 +6,16 @@ Timezone in .at()
 
 Schedule supports setting the job execution time in another timezone using the ``.at`` method.
 
-**To work with timezones** `pytz <https://pypi.org/project/pytz/>`_ **must be installed!** Get it:
-
-.. code-block:: bash
-
-    pip install pytz
-
 Timezones are only available in the ``.at`` function, like so:
 
 .. code-block:: python
 
     # Pass a timezone as a string
     schedule.every().day.at("12:42", "Europe/Amsterdam").do(job)
 
-    # Pass an pytz timezone object
-    from pytz import timezone
-    schedule.every().friday.at("12:42", timezone("Africa/Lagos")).do(job)
+    # Pass a ZoneInfo object
+    from zoneinfo import ZoneInfo
+    schedule.every().friday.at("12:42", ZoneInfo("Africa/Lagos")).do(job)
 
 Schedule uses the timezone to calculate the next runtime in local time.
 All datetimes inside the library are stored `naive <https://docs.python.org/3/library/datetime.html>`_.

pyproject.toml

@@ -9,15 +9,13 @@ dynamic = ["version", "classifiers", "keywords", "authors"]
 readme = "README.rst"
 license = {text = "MIT License"}
 
-requires-python = ">= 3.7"
+requires-python = ">= 3.10"
 dependencies = []
 
 maintainers = [
   {name = "Sijmen Huizenga"}
 ]
 
-[project.optional-dependencies]
-timezone = ["pytz"]
 
 [project.urls]
 Documentation = "https://schedule.readthedocs.io"

requirements-dev.txt

@@ -6,6 +6,4 @@ pytest-flake8
 Sphinx
 black==20.8b1
 click==8.0.4
-mypy
-pytz
-types-pytz
+mypy

schedule/__init__.py

@@ -15,7 +15,7 @@
     - A simple to use API for scheduling jobs.
     - Very lightweight and no external dependencies.
     - Excellent test coverage.
-    - Tested on Python 3.7, 3.8, 3.9, 3.10, 3.11 and 3.12
+    - Tested on Python 3.10, 3.11, 3.12 and 3.13
 
 Usage:
     >>> import schedule
@@ -46,6 +46,7 @@
 import re
 import time
 from typing import Set, List, Optional, Callable, Union
+from zoneinfo import ZoneInfo, ZoneInfoNotFoundError
 
 logger = logging.getLogger("schedule")
 
@@ -486,7 +487,7 @@ def at(self, time_str: str, tz: Optional[str] = None):
             `every().minute.at(':30')`).
 
         :param tz: The timezone that this timestamp refers to. Can be
-            a string that can be parsed by pytz.timezone(), or a pytz.BaseTzInfo object
+            a string accepted by zoneinfo.ZoneInfo(), or a ZoneInfo object
 
         :return: The invoked job instance
         """
@@ -496,16 +497,12 @@ def at(self, time_str: str, tz: Optional[str] = None):
             )
 
         if tz is not None:
-            import pytz
-
             if isinstance(tz, str):
-                self.at_time_zone = pytz.timezone(tz)  # type: ignore
-            elif isinstance(tz, pytz.BaseTzInfo):
+                self.at_time_zone = ZoneInfo(tz)  # type: ignore
+            elif isinstance(tz, ZoneInfo):
                 self.at_time_zone = tz
             else:
-                raise ScheduleValueError(
-                    "Timezone must be string or pytz.timezone object"
-                )
+                raise ScheduleValueError("Timezone must be a string or ZoneInfo object")
 
         if not isinstance(time_str, str):
             raise TypeError("at() should be passed a string")
@@ -733,9 +730,7 @@ def _schedule_next_run(self) -> None:
         while next_run <= now:
             next_run += period
 
-        next_run = self._correct_utc_offset(
-            next_run, fixate_time=(self.at_time is not None)
-        )
+        next_run = self._correct_utc_offset(next_run)
 
         # To keep the api consistent with older versions, we have to set the 'next_run' to a naive timestamp in the local timezone.
         # Because we want to stay backwards compatible with older versions.
@@ -766,55 +761,18 @@ def _move_to_at_time(self, moment: datetime.datetime) -> datetime.datetime:
 
         # When we set the time elements, we might end up in a different UTC-offset than the current offset.
         # This happens when we cross into or out of daylight saving time.
-        moment = self._correct_utc_offset(moment, fixate_time=True)
+        moment = self._correct_utc_offset(moment)
 
         return moment
 
-    def _correct_utc_offset(
-        self, moment: datetime.datetime, fixate_time: bool
-    ) -> datetime.datetime:
+    def _correct_utc_offset(self, moment: datetime.datetime) -> datetime.datetime:
         """
         Given a datetime, corrects any mistakes in the utc offset.
-        This is similar to pytz' normalize, but adds the ability to attempt
-        keeping the time-component at the same hour/minute/second.
         """
         if self.at_time_zone is None:
             return moment
-        # Normalize corrects the utc-offset to match the timezone
-        # For example: When a date&time&offset does not exist within a timezone,
-        # the normalization will change the utc-offset to where it is valid.
-        # It does this while keeping the moment in time the same, by moving the
-        # time component opposite of the utc-change.
-        offset_before_normalize = moment.utcoffset()
-        moment = self.at_time_zone.normalize(moment)
-        offset_after_normalize = moment.utcoffset()
-
-        if offset_before_normalize == offset_after_normalize:
-            # There was no change in the utc-offset, datetime didn't change.
-            return moment
 
-        # The utc-offset and time-component has changed
-
-        if not fixate_time:
-            # No need to fixate the time.
-            return moment
-
-        offset_diff = offset_after_normalize - offset_before_normalize
-
-        # Adjust the time to reset the date-time to have the same HH:mm components
-        moment -= offset_diff
-
-        # Check if moving the timestamp back by the utc-offset-difference made it end up
-        # in a moment that does not exist within the current timezone/utc-offset
-        re_normalized_offset = self.at_time_zone.normalize(moment).utcoffset()
-        if re_normalized_offset != offset_after_normalize:
-            # We ended up in a DST Gap. The requested 'at' time does not exist
-            # within the current timezone/utc-offset. As a best effort, we will
-            # schedule the job 1 offset later than possible.
-            # For example, if 02:23 does not exist (because DST moves from 02:00
-            # to 03:00), this will schedule the job at 03:23.
-            moment += offset_diff
-        return moment
+        return moment.astimezone(datetime.timezone.utc).astimezone(self.at_time_zone)
 
     def _is_overdue(self, when: datetime.datetime):
         return self.cancel_after is not None and when > self.cancel_after

setup.py

@@ -43,13 +43,10 @@ def read_file(filename):
         "Operating System :: OS Independent",
         "Programming Language :: Python",
         "Programming Language :: Python :: 3",
-        "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",
         "Natural Language :: English",
     ],
-    python_requires=">=3.7",
+    python_requires=">=3.10",
 )